Article of footwear with a midsole assembly having a perimeter bladder element, a method of manufacturing and a mold assembly for same

ABSTRACT

An article of footwear has a midsole assembly that includes a fluid-filled bladder element having a substantially arc-shaped heel portion and having a lateral arm portion and a medial arm portion spaced from the lateral arm portion. Each of the arm portions extend from the heel portion. The bladder element is configured to be positioned with the heel portion in the heel region of midsole assembly, and the arm portions extending from the heel region to a forefoot region along a peripheral region. A method of manufacturing and a mold assembly for such an article of footwear are provided.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a divisional application of U.S. application Ser. No.14/832,347, filed on Aug. 21, 2015 and claims the benefit of prioritythereto. U.S. application Ser. No. 14/832,347 claims the benefit ofpriority to U.S. Provisional Application No. 62/073,260 filed on Oct.31, 2014. Both applications are hereby incorporated by reference intheir entirety.

TECHNICAL FIELD

The present disclosure relates to an article of footwear having abladder element and to a method of manufacturing and a mold assembly foran article of footwear.

BACKGROUND

Footwear typically includes a sole configured to be located under awearer's foot to space the foot away from the ground or floor surface.Soles can be designed to provide a desired level of cushioning. Athleticfootwear in particular sometimes utilizes polyurethane foam or otherresilient materials in the sole to provide cushioning. Fluid-filledbladders are sometimes included in the sole to provide desired impactforce absorption, motion control, and resiliency. The incorporation offluid-filled bladders requires additional materials and adds processingsteps to the manufacturing of footwear.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic illustration in exploded perspective view of anembodiment of a midsole assembly including a peripheral fluid-filledbladder element for an embodiment of an article of footwear.

FIG. 2 is schematic illustration in plan view of a first resilientmidsole layer of the midsole assembly of FIG. 1 with an inward extent ofa peripheral region indicated in phantom.

FIG. 3 is a schematic illustration in bottom view of a second resilientmidsole layer of the midsole assembly of FIG. 1 with an inward extent ofa peripheral region indicated in phantom.

FIG. 4 is a schematic illustration in bottom view of the first resilientmidsole layer of FIGS. 1-2 with outsole elements.

FIG. 5 is a schematic illustration in side view of an article offootwear having the midsole assembly of FIG. 1.

FIG. 6 is a schematic illustration in cross-sectional view of anotherembodiment of an article of footwear taken at lines 6-6 in FIG. 7.

FIG. 7 is a schematic illustration in side view of a lateral side of thesecond embodiment of an article of footwear.

FIG. 8 is a flow diagram of a method of manufacturing the articles offootwear of FIGS. 1-7.

FIG. 9 a schematic illustration in cross-sectional view of anotherembodiment of an article of footwear taken at lines 9-9 in FIG. 10.

FIG. 10 is a schematic illustration in side view of a lateral side ofthe article of footwear of FIG. 9.

FIG. 11 is a flow diagram of a method of manufacturing the article offootwear of FIGS. 9-10.

FIG. 12 is a schematic illustration in perspective view of anotherembodiment of a peripheral bladder element.

FIG. 13 is a schematic illustration in cross-sectional view of anotherembodiment of an article of footwear taken at lines 13-13 in FIG. 14.

FIG. 14 is a schematic illustration in side view of a lateral side ofthe article of footwear of FIG. 13.

FIG. 15 is a flow diagram of a method of manufacturing the article offootwear of FIGS. 13-14.

FIG. 16 is a schematic illustration in plan view of a first mold portioncontaining four bladder elements thermoformed therein.

FIG. 17 is a schematic illustration in exploded view of a firstembodiment of a mold assembly including the first mold portion of FIG.16.

FIG. 18 is a cross-sectional illustration of the mold assembly of FIG.17 taken at lines 18-18 in FIG. 17 and with sheets of material for thebladder elements between the mold portions.

FIG. 19 is a cross-sectional illustration of another embodiment of amold assembly with sheets of material for the bladder elements and aco-molded rim between the mold portions.

FIG. 20 is a schematic illustration in fragmentary plan view of a firstmold portion of the mold assembly of FIG. 19.

FIG. 21 is a flow diagram of a method of manufacturing footwear with themold assembly of FIG. 18.

FIG. 22 is a flow diagram of a method of manufacturing footwear with themold assembly of FIG. 19.

FIG. 23 is a schematic illustration in exploded perspective view ofanother embodiment of a midsole assembly including a peripheralfluid-filled bladder element for an embodiment of an article offootwear.

FIG. 24 is a schematic illustration in cross-sectional view of the soleassembly of FIG. 23 in an assembled state.

FIG. 25 is a schematic illustration in cross-sectional view of anarticle of footwear with the sole assembly of FIG. 23 taken at lines25-25 in FIG. 27.

FIG. 26 is a schematic illustration in cross-sectional view of thearticle of footwear of FIG. 25 with the midsole assembly undercompression.

FIG. 27 is a schematic illustration in bottom view of the midsoleassembly of FIG. 23 in an assembled state.

FIG. 28 is a flow diagram of a method of manufacturing the article offootwear of FIG. 23.

FIG. 29 is a schematic illustration in plan view of another embodimentof a bladder element for a midsole assembly.

FIG. 30 is a schematic illustration in plan view of another embodimentof a bladder element for a midsole assembly.

FIG. 31 is a schematic illustration in plan view of another embodimentof a bladder element for a midsole assembly.

FIG. 32 is a schematic illustration in side view of the bladder elementof FIG. 29.

FIG. 33 is a schematic cross-sectional illustration of the bladderelement of FIG. 29 taken at lines 33-33 in FIG. 32.

FIG. 34 is a schematic cross-sectional illustration of the bladderelement of FIG. 29 taken at lines 34-34 in FIG. 32.

FIG. 35 is a schematic cross-sectional illustration of the bladderelement of FIG. 29 taken at lines 35-35 in FIG. 32.

FIG. 36 is a schematic illustration in cross-sectional view of anarticle of footwear with the bladder element of FIG. 29 taken at lines36-36 in FIG. 29 and with midsole layers and outsole elements.

FIG. 37 is a schematic illustration in perspective view of one of themidsole layers of the article of footwear of FIG. 36.

FIG. 38 is a flow diagram of a method of manufacturing the midsoleassembly of FIG. 36.

FIG. 39 is a schematic cross-sectional illustration taken at lines 39-39in FIG. 42 of a heel region of another embodiment an article of footwearincluding a peripheral fluid-filled bladder element.

FIG. 40 is a schematic cross-sectional illustration taken at lines 40-40in FIG. 42 of the article of footwear of FIG. 32.

FIG. 41 is a schematic cross-sectional illustration taken at lines 41-41in FIG. 42 of the article of footwear of FIG. 39.

FIG. 42 is a schematic illustration in side view of the article offootwear of FIGS. 39-41.

FIG. 43 is a flow diagram of a method of manufacturing the article offootwear of FIG. 39.

FIG. 44 is a schematic illustration in bottom view of another embodimentof an article of footwear including a peripheral fluid-filled bladderelement.

FIG. 45 is a schematic cross-sectional illustration taken at lines 45-45in FIG. 44 of the article of footwear of FIG. 44.

FIG. 46 is a schematic cross-sectional illustration taken at lines 46-46in FIG. 44 of the article of footwear of FIG. 44.

FIG. 47 is a schematic illustration in top view of a midsole layer ofthe article of footwear of FIG. 44.

FIG. 48 is a schematic illustration in bottom view of another embodimentof an article of footwear including a peripheral fluid-filled bladderelement.

FIG. 49 is a schematic cross-sectional illustration taken at lines 49-49in FIG. 48 of the article of footwear of FIG. 48.

FIG. 50 is a schematic cross-sectional illustration taken at lines 50-50in FIG. 48 of the article of footwear of FIG. 48.

DETAILED DESCRIPTION

An article of footwear has a midsole assembly that includes afluid-filled bladder element having a substantially arc-shaped heelportion, a lateral arm portion, and a medial arm portion spaced from thelateral arm portion. Each of the arm portions extend from the heelportion. The bladder element is configured to be positioned with theheel portion in a heel region of the article of footwear and the armportions extending from the heel region to a forefoot region of thearticle of footwear along a peripheral region of the article offootwear. The arm portions may have terminal ends positioned in theforefoot region. The bladder element may be substantially transparent.The bladder element arranged at the peripheral region of the article offootwear as described provides a desired level of cushioning whileminimizing material requirements.

In some embodiments, a sole layer with at least one protrusion issecured to the bladder element so that the at least one protrusiondescends into a cavity between the arm portions. The sole layer may be aresilient midsole layer secured to and resting on the bladder element.The at least one protrusion may be configured so that a lowest extent ofthe at least one protrusion terminates above a base surface of thebladder element, ensuring that the at least one protrusion is excludedfrom a ground contact surface of the article of footwear in the absenceof at least a threshold loading force. In embodiments in which there aremultiple protrusions, the resilient midsole layer may form a flex grooveextending generally lengthwise and positioned between at least some ofthe multiple protrusions. The resilient midsole layer may also formlaterally extending grooves between at least some of the multipleprotrusions.

In some embodiments, an additional sole layer is secured to the bladderelement so that the bladder element rests on the additional sole layer.The at least one protrusion may be configured to descend only partiallyinto the cavity between the arm portions in the absence of apredetermined threshold loading force, so that the at least oneprotrusion in the heel region terminates above a base surface of theadditional sole layer, only the additional sole layer thus forming theground contact surface in the heel region in the absence of thepredetermined loading force, while both the midsole layer and theadditional sole layer form the ground contact surface in the forefootregion, even in the absence of the predetermined threshold loadingforce. An additional sole layer may be secured to the bladder element sothat the bladder element rests on the additional sole layer. Theadditional sole layer may have a substantially arc-shaped heel portion,a lateral arm portion, and a medial arm portion corresponding with thearc-shaped heel portion, the lateral arm portion and the medial armportion of the bladder element, respectively. Each of the arm portionsmay extend from the heel portion to the forefoot region along theperipheral region.

The sole layer may be a resilient midsole layer that has a first portionadjacent an inward-facing surface of the bladder element and secured tothe bladder element. In some embodiments, a second portion of theresilient midsole layer adjacent the inward-facing surface of thebladder element is spaced from the bladder element in the absence of atleast a threshold loading force, and is configured to be moved intocontact with the inward-facing surface of the bladder element undercompression by the threshold loading force to attenuate the thresholdloading force. The second portion is configured to have a surfaceprofile substantially identical to a surface profile of theinward-facing surface of the bladder element.

The resilient midsole layer can be configured so that the at least oneprotrusion moves into operative contact with the underlying ground (alsoreferred to as the ground plane) only after the second portion of theresilient midsole layer moves into contact with the inward-facingsurface of the bladder element. The midsole assembly will provide afirst stage of attenuation of the loading force when the second portionof the resilient midsole layer moves into contact with the inward-facingsurface of the bladder element, and will provide a second stage ofattenuation of the loading force when the at least one protrusion movesinto operative contact with the ground plane. A lowest extent of the atleast one protrusion of the midsole layer in the heel region mayterminate above a base surface of the additional sole layer so that theat least one protrusion is excluded from a ground contact surface of thearticle of footwear in the absence of at least the threshold loadingforce, and is configured to move into operative contact with a groundplane under the threshold loading force. At least one outsole elementmay be secured to the at least one protrusion such that the at least oneoutsole element is excluded from the ground contact surface of thearticle of footwear in the absence of at least the threshold loadingforce, and contacts the ground plane only under the threshold loadingforce.

In some embodiments, the bladder element includes only the heel portionand arm portions. In other embodiments, the bladder element forms a webconnecting the arm portions. The bladder element may be formed from anupper sheet and a lower sheet, such as polymeric sheets. The sheets ofthe bladder element may form fluid-filled pods in the web that may bedownwardly-extending protrusions. The pods may be at ambient pressure ormay be pressurized. An additional sole layer may be secured to thebladder element, and may have apertures configured to receive andsupport the fluid-filled pods of the web. In order to provide thefluid-filled pods as part of the web, the bladder element can have aninner flange at which the sheets are joined at an inward-facing surfaceof the bladder element. The inner flange may form a seam that may bereferred to as a roll seam, and that progresses upward along the armportions from the heel portion toward the terminal ends. In anotherembodiment, the bladder element has an inner flange forming an innerseam at which the sheets are joined at an inward-facing surface of thebladder element, and an outer flange forming an outer seam where thesheets are joined at an outward-facing surface of the bladder element.The inner flange and the outer flange are generally at an upper portionof the bladder element from the heel portion to the terminal ends, andthe outer flange is tapered and extends generally upward. The outer seammay be referred to as a swept pinch seam, and enables an upper of thearticle of footwear to be secured to the bladder element at the outerflange. At least a portion of the outer flange may have a thickness incross-section greater than a sum of the thicknesses of the upper andlower sheets away from the outer flange. A footwear upper may be securedto and cupped by the outer flange.

In some embodiments, the midsole assembly may include a first resilientmidsole layer having a heel region, a forefoot region, and a peripheralregion corresponding with the heel region, the forefoot region, and theperipheral region of the article of footwear, respectively. Thefluid-filled bladder element may be supported on the first resilientmidsole layer and positioned substantially at the peripheral region ofthe first resilient midsole layer. In some embodiments, an overlayingcomponent is supported on the bladder element above the first resilientmidsole layer such that an internal chamber at least partially definedby the first resilient midsole layer is sealed by the first resilientmidsole layer, the overlaying component, and the bladder element. Theinternal chamber may include one or more recesses in the first resilientmidsole layer. The first resilient midsole layer may have a recess inthe heel region of the first resilient midsole layer. The recess may atleast partially define the internal chamber. The first resilient midsolelayer may have a recess in the forefoot region that at least partiallydefines the internal chamber. The recesses may contain air at ambientpressure. The recesses affect flexibility and cushioning of the firstresilient midsole layer. In some embodiments, the recesses are closed bythe overlaying component so that the internal chamber functionssimilarly to a bladder element. An outsole element may be secured to atleast a portion of a bottom surface of the first resilient midsolelayer. At least a portion of a bottom surface of the first resilientmidsole layer may have laterally-extending grooves.

The bladder element may have a base surface supported on the firstresilient midsole layer. The bladder element may taper from the basesurface to a peak extending along the bladder element opposite the basesurface and the first resilient midsole layer. The bladder element mayhave a generally outward-facing side surface between the base surfaceand the peak, and a generally inward-facing side surface between thebase surface and the peak. The overlaying component may be supported onthe inward-facing side surface so that at least a portion of theoutward-facing side surface of the bladder element is exposed.

In some embodiments, the overlaying component is part of the midsoleassembly. For example, the overlaying component may be a secondresilient midsole layer secured to the bladder element. The firstresilient midsole layer may have a first hardness, and the secondresilient midsole layer may have a second hardness greater than thefirst hardness. In such an embodiment, a footwear upper may bedouble-lasted to the second resilient midsole layer such that thefootwear upper covers the side surfaces and the bottom surface of thesecond resilient midsole layer and is in contact with the bladderelement. The second resilient midsole layer may have a lower surfacewith a peripheral cavity configured to receive the bladder element.

In some embodiments, the overlaying component is a footwear upper, and arim is secured to and rims the bladder element. The footwear upper issecured to the rim so that the rim separates the upper and the bladderelement. The rim may be co-molded with the bladder element. The rim mayhave a flange with a generally exterior-facing surface and a generallyinterior-facing surface. The footwear upper may be secured to theinterior-facing surface of the flange so that the exterior-facingsurface of the flange is exposed on the article of footwear. The rim maybe substantially transparent.

In some embodiments, the midsole assembly includes a resilient midsolelayer secured to and resting on the bladder element and having at leastone protrusion that extends only partially into a cavity formed betweenthe arm portions in the heel regions in the absence of at least athreshold loading force. An additional sole layer is secured to thebladder element and the bladder element rests on the additional solelayer. The additional sole layer has a substantially arc-shaped heelportion to which the heel portion of the bladder element is secured, alateral arm portion to which the lateral arm portion of the bladderelement is secured, and a medial arm portion to which the medial armportion of the bladder element is secured. The additional sole layerthereby extends with the bladder element from the heel region to theforefoot region along the peripheral region and around the cavity. Insuch an embodiment, the midsole layer may have a first hardness, and theadditional sole layer may have a second hardness greater than the firsthardness.

A first portion of the resilient midsole layer adjacent an inward-facingsurface of the bladder element may be secured to the bladder element. Asecond portion of the resilient midsole layer adjacent the inward-facingsurface of the bladder element may be spaced from the bladder element inthe absence of at least a threshold loading force and is configured tobe moved into contact with the inward-facing surface of the bladderelement under compression by the threshold loading force to attenuatethe threshold loading force. The second portion may have a surfaceprofile substantially identical to a surface profile of theinward-facing surface of the bladder element. A lowest extent of the atleast one protrusion of the midsole layer in the heel region mayterminate above a base surface of the additional sole layer so that theat least one protrusion is excluded from a ground contact surface of thearticle of footwear in the absence of at least the threshold loadingforce, and is configured to move into operative contact with a groundplane under the threshold loading force. A lowest extent of at least oneprotrusion of the midsole layer in the forefoot region may be includedin the ground contact surface of the article of footwear even in theabsence of the threshold loading force. The midsole assembly may providea first stage of attenuation of at least the threshold loading forceprior to the at least one protrusion of the midsole layer in the heelregion moving into operative contact with the ground plane, and mayprovide a second stage of attenuation of at least the threshold loadingforce when the at least one protrusion of the midsole layer in the heelregion moves into operative contact with the ground plane.

In some embodiments, only the additional sole layer forms a groundcontact surface in the heel region in the absence of a predeterminedthreshold loading force, and both the midsole layer and the additionalsole layer form the ground contact surface in the forefoot region evenin the absence of the predetermined threshold loading force. In someembodiments, the at least one protrusion may include only a singleprotrusion in the heel region that tapers laterally inward, away fromthe arm portions of the bladder element, to the lowest extent. Themidsole layer may have at least one cavity defining or supporting atleast one ambient air pod. The midsole assembly may further include aplate molded to the bladder element and extending between the lateralarm portion and the medial arm portion in the forefoot region.

A method of manufacturing an article of footwear includes providing abladder element formed from first and second polymeric sheets so thatthe bladder element has a substantially arc-shaped heel portion, alateral arm portion, and a medial arm portion laterally-spaced from thelateral arm portion, and with the lateral arm portion and the medial armportion each extending from the heel portion. The method may includesecuring a sole layer to at least a portion of the bladder element, andpositioning the sole layer so that at least one protrusion of the solelayer descends into a lateral space between the arm portions. Anadditional sole layer may also be secured to at least one of the bladderelement and the at least one protrusion under the method. In embodimentsin which the at least one protrusion includes multiple protrusions, themethod may include providing at least one groove between at least someof the multiple protrusions.

In embodiments in which the bladder element has ambient pods formedbetween the arm portions, and the sole layer has apertures through whichthe ambient pods partially extend so that the sole layer cups theambient pods, the method may include securing outsole elements onportions of the ambient pods that extend through the apertures.

The method may include forming the bladder element. In embodiments inwhich the first and second polymeric sheets extend between the armportions to form a web, forming the bladder element includes molding thepolymeric sheets to form sealed fluid-filled pods in the web. In someembodiments, forming the bladder element may further include joining thepolymeric sheets at an inner flange by a roll seam that progressesupward toward terminal ends of the arm portions. In still furtherembodiments, forming the bladder element may include joining thepolymeric sheets at an outer seam at an outward-facing surface of thebladder element, and at an inner flange at an inward-facing surface ofthe bladder element. In such embodiments, the inner flange and the outerflange are generally at an upper portion of the bladder element from theheel portion to terminal ends of the arm portions, and the outer flangeextends generally upward. The method may further include securing afootwear upper to the outer flange such that the outer flange is exposedon the article of footwear.

In some embodiments, the bladder element may be supported substantiallyon a peripheral region of the sole layer, and the method may includesupporting an overlaying component on the bladder element so that theoverlaying component extends above the sole layer and so that aninternal chamber at least partially defined by the sole layer is sealedbetween the sole layer, the overlaying component, and the bladderelement. The method may include co-molding a rim to the bladder element,and securing the overlaying component to the rim. The method may includesecuring the overlaying component to the bladder element. Still further,the method may include securing a footwear upper to the overlayingcomponent.

In some embodiments, the bladder element is a first bladder element andthe article of footwear is a first article of footwear. In suchembodiments, the method may include simultaneously forming the firstbladder element and a second bladder element for a second article offootwear in a single mold assembly. The second bladder element may havea substantially arc-shaped heel portion, a lateral arm portion, and amedial arm portion with the lateral arm portion and the medial armportion each extending from the heel portion. The medial arm portion ofthe first bladder element may be between the lateral and medial armportions of the second bladder element during the forming. The firstbladder element may have one of a right foot orientation and a left footorientation, and the second bladder element may have the same said oneof a right foot orientation and a left foot orientation as the firstbladder element. The forming may be thermoforming first and secondpolymeric sheets, and may further include trimming a bonded flange at aperimeter of each of the first bladder element and the second bladderelement.

Simultaneously forming in the single mold assembly may further includeforming a third bladder element and a fourth bladder element. Each ofthe third bladder element and the fourth bladder element may have asubstantially arc-shaped heel portion, a lateral arm portion, and amedial arm portion with the lateral arm portion and the medial armportion each extending from the heel portion. The medial arm portion ofthe third bladder element may be between the lateral and medial armportions of the fourth bladder element during the forming. In oneembodiment, the first bladder element has one of a right footorientation and a left foot orientation, and the second bladder elementhas the same said one of a right foot orientation and a left footorientation as the first bladder element, and the third bladder elementand the fourth bladder element are both of the other of said right footorientation and said left foot orientation. In such an embodiment, thelateral arm portion of the second bladder element may be adjacent to thelateral arm portion of the third bladder element during said forming. Arespective rim may be co-molded to each of the first bladder element andthe second bladder element in the single mold assembly under the method.

A method of manufacturing an article of footwear may includesimultaneously forming a first bladder element for a first article offootwear and a second bladder element for a second article of footwearin a single mold assembly. Each of the first bladder element and thesecond bladder element may have a substantially arc-shaped heel portion,a lateral arm portion, and a medial arm portion, with the lateral armportion and the medial arm portion each extending from the heel portion.The medial arm portion of the first bladder element may be between thelateral and medial arm portions of the second bladder element during theforming. The first bladder element may have one of a right footorientation and a left foot orientation, and the second bladder elementmay have the same said one of a right foot orientation and a left footorientation as the first bladder element. Simultaneously forming in thesingle mold assembly may further include forming a third bladder elementand a fourth bladder element. Each of the third bladder element and thefourth bladder element may have a substantially arc-shaped heel portion,a lateral arm portion, and a medial arm portion with the lateral armportion and the medial arm portion each extending from the heel portion.The medial arm portion of the third bladder element may be between thelateral and medial arm portions of the fourth bladder element duringsaid forming. The third bladder element and the fourth bladder elementmay both of the other of said right foot orientation and said left footorientation than the first and the second bladder element. The lateralarm portion of the second bladder element may be adjacent to the lateralarm portion of the third bladder element during said forming. Arespective rim may be co-molded to each of the first bladder element andthe second bladder element in the single mold assembly under the method.Forming may be thermoforming first and second polymeric sheets, and mayfurther include trimming a bonded flange at a perimeter of each of thefirst bladder element and the second bladder element.

The unique shape of the bladder element enables a novel mold assemblyand an efficient method of manufacturing bladder elements using the moldassembly. The mold assembly for bladder elements used in articles offootwear may include a mold portion that defines a first mold cavity anda second mold cavity. Each of the first mold cavity and the second moldcavity may have a substantially arc-shaped heel cavity portion, alateral arm cavity portion, and a medial arm cavity portion. The lateralarm cavity portion and the medial arm cavity portion may each extendfrom and may be continuous with the heel cavity portion. The medial armcavity portion of the first mold cavity may be between the lateral andmedial arm cavity portions of the second mold cavity. The medial armcavity portion of the first mold cavity may extend generally toward theheel cavity portion of the second mold cavity, and the medial arm cavityportion of the second mold cavity may extend generally toward the heelcavity portion of the first mold cavity. This arrangement enablesmolding of multiple bladder elements simultaneously, potentiallyreducing processing time and cost. When polymeric sheets and/or othermaterials are used in the mold assembly to create the bladder elements,such as by thermoforming, the arrangement of the mold cavity portionsminimizes scrap material.

In some embodiments, a first distance from an outer edge of the lateralarm cavity portion of the first mold cavity to an outer edge of thelateral arm cavity portion of the second mold cavity is less than twicea second distance from an outer edge of the medial arm cavity portion ofthe first mold cavity to an outer edge of the lateral arm cavity portionof the first mold cavity. The first distance and the second distance maybe determined along a common cross section extending across the medialand lateral arm cavity portions of the first and second mold cavities.

In some embodiments, the mold portion is a first mold portion, and themold assembly may also include a second mold portion that has moldcavities configured to correspond with the substantially arc-shaped heelcavity portions, the lateral arm cavity portions, and the medial armcavity portions of the first and second mold cavities of the first moldportion when the second mold portion is placed adjacent to the firstmold portion so that the mold cavities of the first and second moldportions together define molds for first and second bladder elements,each of the bladder elements having a substantially arc-shaped heelportion, a lateral arm portion, and a medial arm portion, with thelateral arm portion and the medial arm portion each extending from thesubstantially arc-shaped heel portion. The mold cavities of one of thefirst and the second mold portions may each be configured with a rimportion extending along the substantially arc-shaped heel cavityportion, the lateral arm cavity portion, and the medial arm cavityportion.

In some embodiments, the mold portion may further define a third moldcavity and a fourth mold cavity. Each of the third mold cavity and thefourth mold cavity may have a substantially arc-shaped heel cavityportion, a lateral arm cavity portion, and a medial arm cavity portionwith the lateral arm cavity portion and the medial arm cavity portioneach extending from and being continuous with the heel cavity portion.The medial arm cavity portion of the third mold cavity may be betweenthe lateral and medial arm cavity portions of the fourth mold cavity.The medial arm cavity portion of the third mold cavity may extendgenerally toward the heel cavity portion of the fourth mold cavity. Themedial arm cavity portion of the fourth mold cavity may extend generallytoward the heel cavity portion of the third mold cavity. A thirddistance from an outer edge of the lateral arm cavity portion of thethird mold cavity to an outer edge of the lateral arm cavity portion ofthe fourth mold cavity may be less than twice a fourth distance from anouter edge of the medial arm cavity portion of the third mold cavity toan outer edge of the lateral arm cavity portion of the third moldcavity. The third distance and the fourth distance are determined alonga common cross section extending across the medial and lateral armcavity portions of the third and fourth mold cavities. A lateral armcavity portion of the second mold cavity is adjacent the lateral armcavity portion of the third mold cavity.

The mold portion may have a first end and a second end opposite thefirst end. The heel cavity portions of the second and third moldcavities may be positioned such that the arm cavity portions of thesecond and third mold cavities extend generally toward the first end ofthe mold portion. The heel cavity portions of the first and fourth moldcavities may be positioned such that the arm cavity portions of thefirst and fourth mold cavities extend toward the second end of the moldportion.

In some embodiments, the mold portion is a first mold portion, and themold assembly further includes a second mold portion having moldcavities configured to correspond with the substantially arc-shaped heelcavity portions, the lateral arm cavity portions, and the medial armcavity portions of the first, second, third, and fourth mold cavities ofthe first mold portion when the second mold portion is placed adjacentto the first mold portion so that the mold cavities of the first andsecond mold portions together define molds for the first, second, third,and fourth bladder elements. Each of the bladder elements may have asubstantially arc-shaped heel portion, a lateral arm portion, and amedial arm portion, with the lateral arm portion and the medial armportion each extending from the substantially arc-shaped heel portion.The mold cavities of one of the first and the second mold portions mayeach be configured with a rim portion extending along the substantiallyarc-shaped heel cavity portion, the lateral arm cavity portion, and themedial arm cavity portion.

The above features and advantages and other features and advantages ofthe present teachings are readily apparent from the following detaileddescription of the modes for carrying out the present teachings whentaken in connection with the accompanying drawings.

“A,” “an,” “the,” “at least one,” and “one or more” are usedinterchangeably to indicate that at least one of the items is present. Aplurality of such items may be present unless the context clearlyindicates otherwise. All numerical values of parameters (e.g., ofquantities or conditions) in this specification, unless otherwiseindicated expressly or clearly in view of the context, including theappended claims, are to be understood as being modified in all instancesby the term “about” whether or not “about” actually appears before thenumerical value. “About” indicates that the stated numerical valueallows some slight imprecision (with some approach to exactness in thevalue; approximately or reasonably close to the value; nearly). If theimprecision provided by “about” is not otherwise understood in the artwith this ordinary meaning, then “about” as used herein indicates atleast variations that may arise from ordinary methods of measuring andusing such parameters. In addition, a disclosure of a range is to beunderstood as specifically disclosing all values and further dividedranges within the range.

The terms “comprising,” “including,” and “having” are inclusive andtherefore specify the presence of stated features, steps, operations,elements, or components, but do not preclude the presence or addition ofone or more other features, steps, operations, elements, or components.Orders of steps, processes, and operations may be altered when possible,and additional or alternative steps may be employed. As used in thisspecification, the term “or” includes any one and all combinations ofthe associated listed items. The term “any of” is understood to includeany possible combination of referenced items, including “any one of” thereferenced items. The term “any of” is understood to include anypossible combination of referenced claims of the appended claims,including “any one of” the referenced claims.

Those having ordinary skill in the art will recognize that terms such as“above,” “below,” “upward,” “downward,” “top,” “bottom,” etc., are useddescriptively relative to the figures, and do not represent limitationson the scope of the invention, as defined by the claims.

Referring to the drawings, wherein like reference numbers refer to likecomponents throughout the several views, FIG. 1 is an explodedperspective view of an embodiment of a midsole assembly 10 for anarticle of footwear 12 shown in FIG. 5. The midsole assembly 10 includesa first resilient midsole layer 14 and a fluid-filled bladder element 16configured to cooperatively fit to the first resilient midsole layer 14so that the bladder element 16 is supported on and secured to aperipheral region 22 of the first resilient midsole layer 14 as shown inFIG. 5 and as further discussed herein. As used herein, a “peripheralregion” is a region between a center region and a perimeter of anobject. An overlaying component 18, which in this embodiment is a secondresilient midsole layer 18, is configured to cooperatively fit to thebladder element 16 to rest above the bladder element 16 and the firstresilient midsole layer 14. When the bladder element 16 is secured tothe first resilient midsole layer 14 and the second resilient midsolelayer 18 as described herein, an internal chamber 20 is formed by andbetween the first resilient midsole layer 14, the second resilientmidsole layer 18, and the bladder element 16. The internal chamber 20may be at an ambient pressure, but may be sealed by the first resilientmidsole layer 14 and the second resilient midsole layer 18. A portion ofthe internal chamber 20 is visible through the bladder element 16 inFIG. 5.

Referring again to FIG. 1, the bladder element 16 is an elongatedelement configured to be supported on and secured to a peripheral region22 of the first resilient midsole layer 14. The bladder element 16 has asubstantially arc-shaped heel portion 24, that can also be referred toas a U-shaped heel portion, and has a medial arm portion 26A and alateral arm portion 26B each extending from the heel portion 24. Theheel portion 24 is configured to be located at the heel region 28 of thefirst resilient midsole layer 14 as discussed herein. The bladderelement 16 can be formed from a variety of materials including variouspolymers that can resiliently retain a fluid such as air or another gas.Examples of polymer materials for bladder element 16 includethermoplastic urethane, polyurethane, polyester, polyester polyurethane,and polyether polyurethane. Moreover, the bladder element 16 can beformed of layers of different materials. In one embodiment, the bladderelement 16 is formed from thin films having one or more thermoplasticpolyurethane layers with one or more barriers layer of a copolymer ofethylene and vinyl alcohol (EVOH) that is impermeable to the pressurizedfluid contained therein as disclosed in U.S. Pat. No. 6,082,025, whichis incorporated by reference in its entirety. Bladder element 16 mayalso be formed from a material that includes alternating layers ofthermoplastic polyurethane and ethylene-vinyl alcohol copolymer, asdisclosed in U.S. Pat. Nos. 5,713,141 and 5,952,065 to Mitchell et al.which are incorporated by reference in their entireties. Alternatively,the layers may include ethylene-vinyl alcohol copolymer, thermoplasticpolyurethane, and a regrind material of the ethylene-vinyl alcoholcopolymer and thermoplastic polyurethane. The bladder element 16 mayalso be a flexible microlayer membrane that includes alternating layersof a gas barrier material and an elastomeric material, as disclosed inU.S. Pat. Nos. 6,082,025 and 6,127,026 to Bonk et al. which areincorporated by reference in their entireties. Additional suitablematerials for the bladder element 16 are disclosed in U.S. Pat. Nos.4,183,156 and 4,219,945 to Rudy which are incorporated by reference intheir entireties. Further suitable materials for the bladder element 16include thermoplastic films containing a crystalline material, asdisclosed in U.S. Pat. Nos. 4,936,029 and 5,042,176 to Rudy, andpolyurethane including a polyester polyol, as disclosed in U.S. Pat.Nos. 6,013,340, 6,203,868, and 6,321,465 to Bonk et al. which areincorporated by reference in their entireties. In selecting materialsfor the bladder element 16, engineering properties such as tensilestrength, stretch properties, fatigue characteristics, dynamic modulus,and loss tangent can be considered. The thicknesses of sheets ofmaterials used to form the bladder element 16 can be selected to providethese characteristics.

The bladder element 16 is resilient and provides cushioning andflexibility that can be tuned such as by selecting a level ofpressurization. Tensile members and/or reinforcing structures can beintegrated with the bladder element 16 to provide desiredresponsiveness, such as disclosed in U.S. Pat. No. 4,906,502 to Rudy etal., and U.S. Pat. No. 8,061,060 to Swigart et al., which areincorporated by reference in their entireties.

The first resilient midsole layer 14 is a unitary layer configured toextend the entire underfoot region of the article of footwear 12. In oneembodiment, the first resilient midsole layer 14 may be a polymer foammaterial such as polyurethane or ethylene vinyl acetate (EVA).Alternatively, the first resilient midsole layer 14 may be a bladderelement formed of any of the materials described with respect to bladderelement 16. As shown in FIG. 5, the article of footwear 12 is anathletic shoe. In other embodiments, the midsole assembly 10 could befor an article of footwear that is a dress shoe, a work shoe, a sandal,a slipper, a boot, or any other category of footwear. The firstresilient midsole layer 14 has a heel region 28, a forefoot region 30,and a midfoot region 32 there between. Heel region 28 generally includesportions of the first resilient midsole layer 14 corresponding with rearportions of a human foot of a size corresponding with the article offootwear 12, including the calcaneus bone. Forefoot region 30 generallyincludes portions of the first resilient midsole layer 14 correspondingwith the toes and the joints connecting the metatarsals with thephalanges of a human foot of a size corresponding with the article offootwear 12. Midfoot region 32 generally includes portions of the firstresilient midsole layer 14 corresponding with an arch area of a humanfoot of a size corresponding with the article of footwear 12. As usedherein, a lateral side of a component for an article of footwear, suchas a lateral side of the first resilient midsole layer, is a side thatcorresponds with an outside area of the foot of the wearer of thearticle of footwear that is generally further from the other foot of thewearer (i.e., the side closer to the fifth toe of the wearer). The fifthtoe is commonly referred to as the little toe. A medial side of acomponent for an article of footwear, such as a medial side of the firstresilient midsole layer 14, is the side that corresponds with an insidearea of the foot on which the article of footwear is worn and that isgenerally closer to the other foot of the wearer (i.e., the side closerto the hallux of the foot of the wearer). The hallux is commonlyreferred to as the big toe. In the embodiment of the first resilientmidsole layer 14 shown in FIG. 2, the heel region 28 extends from a rearextremity at boundary A to boundary B. Boundary B corresponds with aforward-most portion of an arcuate ridge 76 of central raised portion 38described herein. Midfoot region 32 extends from boundary B to boundaryC. Boundary C is at a rearward-most portion of recess 74C. Forefootregion 30 extends from boundary C to boundary D at a forward extremityof the first resilient midsole layer 14.

The peripheral region 22 of the first resilient midsole layer 14 is aregion extending from the outer perimeter 34 of the first resilientmidsole layer 14 slightly inward to a boundary generally established bya raised central portion 38. The inward extent of the peripheral region22 is indicated with phantom boundary 36 in FIG. 2. In the embodimentshown, the peripheral region 22 extends inward from an outer perimeter34 of the first resilient midsole layer 14 to boundary 36 coincidingwith the edges of a central raised portion 38 described herein. In FIG.2, the boundary 36 is shown slightly offset from the edge of the centralraised portion 38 in order to make phantom line 36 visible. In the heelregion 28, the boundary 36 generally continues from the edge of theraised central portion 38 and follows the contours of the outerperimeter 34.

The first resilient midsole layer 14 is configured with a central raisedportion 38 inward of the peripheral region 22. Side surfaces 40A, 40B ofthe central raised portion 38 extend upward from an upward facingsurface 42 to form a medial side recess 44A and a lateral side recess44B. The side recesses 44A, 44B extend along the peripheral region 22from the heel region 28 to forward ends 46A, 46B, respectively. The siderecesses 44A, 44B and the heel region 28 are configured to becomplementary to the shape of the bladder element 16 so that the bladderelement 16 can be supported on the first resilient midsole layer 14 withthe heel portion 24 supported at the peripheral region 22 at the heelregion 28, with the medial arm portion 26A fit in the side recess 44A,and with the lateral arm portion 26B fit in the side recess 44B. Whenfit to the first resilient midsole layer 14 in this manner, a terminalend 48A of the medial arm portion 26A rests at the forward end 46A ofthe side recess 44A, and a terminal end 48B of the lateral arm portion26B rests at the forward end 46B of the side recess 44B. The terminalends 48A, 48B are thus rearward of a forward-most portion 50 of theperipheral region 22. As shown in FIG. 1, the first resilient midsolelayer 14 has an upwardly-extending lip 52 at the forward-most portion 50of the peripheral region 22. The first resilient midsole layer 14 has aseries of notches 51 in the peripheral region 22 at the medial side 53of the first resilient midsole layer 14 that provide flexibility in anarch region. A lateral side 55 of the first resilient midsole layer 14is without notches in the embodiment shown, but may also be notched. Thenotches 51 can be configured so that when the medial arm portion 26A ofthe bladder element seats at the peripheral region 22 of the firstresilient midsole layer 14, the notches 51 are open at an underside. Themidsole layer flexes at the notches, and the bottom surface of themidsole layer 14 can have an outsole layer to provide increasedtraction.

Referring now to FIGS. 1 and 3, the midsole assembly 10 includes theoverlaying element 18 which in this embodiment is a second resilientmidsole layer 18 that is a unitary layer configured to extend the entireunderfoot region of the article of footwear 12. The second resilientmidsole layer 18 may be a polymer foam material similar to the firstresilient midsole layer 14. Alternatively, the second resilient midsolelayer 18 may be a non-foam polymer material with a durometer selected tobe relatively low or relatively high in comparison to the firstresilient midsole layer 14, as desired. The second resilient midsolelayer 18 has an upper surface 54 that faces generally upward when thesecond resilient midsole layer 18 is assembled in the article offootwear 12, and a lower surface 56 that faces generally downward whenthe second resilient midsole layer 18 is assembled in the article offootwear 12. FIG. 3 shows that a peripheral region 58 of the secondresilient midsole layer 18 is a region extending from an outer perimeter60 of the second resilient midsole layer 18 slightly inward. The inwardextent of the peripheral region 58 is indicated with phantom line 61 inFIGS. 2 and 3.

The second resilient midsole layer 18 is configured with a centralraised portion 62 inward of the peripheral region 58. Side surfaces 64A,64B of the central raised portion 62 extend downward from adownward-facing surface 46 to form a medial side recess 66A and alateral side recess 66B. The side recesses 66A, 66B extend along theperipheral region 58 from a heel portion 68 to forward ends 70A, 70B,respectively. The central raised portion 62 and downward-facing surface46 also define a recess 71 at the heel region 68. The heel recess 71joins the side recesses 66A, 66B to define together with the siderecesses 66A, 66B a peripheral cavity 66A, 71, 66B configured to receivethe bladder element 16. The side recesses 66A, 66B and the heel recess71 are configured to be complementary to the shape of the bladderelement 16 so that the second resilient midsole layer 18 can besupported on the bladder element 16 with the heel portion 24 supportedin the heel recess 71, with the medial arm portion 26A fit in the siderecess 66A, and with the lateral arm portion 26B fit in the side recess66B. When fit to the second resilient midsole layer 18 in this manner, aterminal end 48A of the medial arm portion 26A rests at the forward end70A of the side recess 66A, and a terminal end 48B of the lateral armportion 26B rests at the forward end 70B of the side recess 66B. Theterminal ends 48A, 48B are thus rearward of a forward-most portion 63 ofthe peripheral region 58. As shown in FIG. 1, the second resilientmidsole layer 18 has a downward-extending lip 72 at the forward-mostportion 63 of the peripheral region 58.

When assembled in this manner and secured to one another under any ofthe methods described herein, the internal chamber 20 indicated in FIG.5 is formed between the arm portions 26A, 26B, above the first resilientmidsole layer 14, and below the second resilient midsole layer 18. Thelip 72 of the second resilient midsole layer 18 and the lip 52 of thefirst resilient midsole layer 14 can be secured to one another asdescribed herein to close the forward portion of the midsole assembly10. The first resilient midsole layer 14, the bladder element 16 and thesecond resilient midsole layer 18 thus define and seal the internalchamber 20. The internal chamber 20 may contain air at ambient pressure.The chamber 20 can extend forward of the heel region 28 between thefirst resilient midsole layer 14 and the second resilient midsole layer18, or all or only portions of the central raised portion 62 of thesecond resilient midsole layer 18 can be in contact with portions of thecentral raised portion 38 of the first resilient midsole layer 14 underall conditions, or only under a predetermined amount and distribution ofdownward force on the midsole assembly 10. The foam layers 14, 18 may bemore resilient than the bladder element 16, such that the bladderelement 16 provides a desirable level of support and stability along theperimeter 22 at the heel region 28 and in the recesses 44A, 44B, while agreater cushioned response is provided in the midfoot region 32 and theforefoot region 30.

Additionally, a greater stiffness of the bladder element 16 will causethe bladder element 16 to be biased toward the unflexed position shownin FIG. 1. If the forefoot region 30 is flexed relative to the midfootregion 32 and the heel region 28, the arm portions 26A, 26B will alsoflex due to proximity to and termination near the forefoot region 30.The arm portions 26A, 26B will urge the forefoot region 30 to theunflexed position of FIG. 1, causing the forefoot region 30 to snap backto the unflexed position when the force flexing the forefoot region 30lessens. The first resilient midsole layer 14 may have a first hardness,and the second resilient midsole layer 18 may be configured to have asecond hardness that is greater than the first hardness. By providingthe second resilient midsole layer 18 with a greater hardness,additional support and motion control relative to the bladder element 16is provided for the foot of a wearer.

The central raised portion 38 of the first resilient midsole layer 14ends at an arcuate ridge 76 of the central raised portion 38 forward ofthe heel region 28, and a surface 78 of the central raised portion 38gradually tapers slightly rearward to the upward-facing surface 42. Thetaper of the surface 78 may be configured to match the curvature of thegenerally inward-facing surface 80 of the bladder element 16, enablingthe bladder element 16 to be supported at and secured to the secondresilient midsole layer 18 at the inward-facing surface 80. In thismanner, a generally-outward-facing surface 82 of the bladder element 16is unobstructed by the second resilient midsole layer 18, and is exposedon the article of footwear 12. Additionally, the bladder element 16 maybe a substantially transparent material so that a view through theentire bladder element 16 from the lateral side 55 shown in FIG. 5 tothe medial side 53 at the heel region 28 is possible. As used herein, acomponent is “substantially transparent” when it is sufficientlytransparent to allow at least some light to pass through, therebyallowing visibility there through. A substantially transparent item maybe translucent, and may be clear or may have a tinted color.

When the heel portion 24 of the bladder element 16 extends along theperipheral region 22 at the heel region 28, an internal chamber 74A isdefined at the heel region 28 between the central raised portion 38 andthe heel portion 24. The internal chamber 74A opens to the internalchamber 20. The first resilient midsole layer 14 can also be providedwith one or more recesses in either or both of the midfoot region 32 orthe forefoot region 30. FIG. 1 shows two interconnected recesses 74B,74C between the forefoot region 30 and the midfoot region 32. Therecesses 74B, 74C may also be referred to as internal chambers or may becontinuous with the internal chamber 20 depending on whether the centralraised portion 62 is configured to interact with the raised portion 38in a manner that seals the recesses 74A, 74B. In the embodiment shown,the second resilient midsole layer 18 serves to close off the internalchamber 20 and the recesses 74B, 74C, creating pods of ambient air atthe internal chamber 20 and the recesses 74B, 74C that function similarto the bladder element 16 without the addition of components. That is,the recesses 74A, 74B, 74C are void of material, allowing the materialof the foam layers 14, 18 bordering the recesses 74A, 74B, 74C greaterability to compress during load-bearing impact, providing energyabsorption to create a desirable underfoot feel. Optionalupwardly-extending protrusions 74D, 74E of the first resilient midsolelayer 14 extend toward the upper foam layer 18 and fill a portion of therecesses 74B, 74C. The configuration of the protrusions 74D, 74E can betuned to control contact of the first resilient midsole layer 14 withthe second resilient midsole layer 18 at the recesses 74B, 74C.Cushioning with a first energy absorption characteristic occurs in afirst stage of compression prior to full contact of the first resilientmidsole layer 14 with the second resilient midsole layer 18, andcushioning with a second energy absorption characteristic occurs in asecond stage of compression after full contact of the first resilientmidsole layer 14 with the second resilient midsole layer 18. In otherembodiments, additional bladder elements can be placed in the recesses74B, 74C.

FIG. 4 shows a bottom surface 84 of the first resilient midsole layer 14that serves as a ground contacting surface. The bottom surface 84 canhave a variety of textures and formations. In the embodiment shown, thebottom surface 84 has a plurality of laterally-extending grooves 85 thatpromote flexibility of the first resilient midsole layer 14. Grooves 87extending generally fore-aft are also provided. In one embodiment, aplurality of outsole elements 86A, 86B, 86C of a highly durable materialsuch as rubber are secured to the bottom surface 84 in high wear areas.In an alternative embodiment in which the first resilient midsole layer14 is a bladder element, the outsole elements 86A, 86B, 86C arecoextruded with the bladder element material of the first resilientmidsole layer 14. In such an embodiment, the first resilient midsolelayer 14 and the outsole elements 86A, 86B, 86C are a single,integrated, one-piece component, over which the overlaying component 18is laid to seal off the recesses 74A, 74B, 74C. In still otherembodiments, the bottom surface 84 alone can serve as the groundcontacting surface without the addition of outsole elements. In eitherinstance, the first resilient midsole layer 14 of the midsole assembly10 can be referred to as a unisole, because the first resilient midsolelayer 14 and midsole assembly 10 are configured such that a conventionalfull-length outsole need not be provided.

A footwear upper 31 is secured to the second resilient midsole layer 18by any suitable manner, such as adhesives, stitching, a combination ofthese methods, or otherwise. In the embodiment shown, the upper 31 isadhered to a perimeter of the second resilient midsole layer 18. Astrobel unit can be adhered to the upper 31 and can overlay and beadhered to the upper surface 54 of the second resilient midsole layer18. The footwear upper 31 may include multiple textile layers hot-meltedtogether with TPU or polymer foam. A fabric net can also be integratedin the upper 31, and stretched as desired prior to hot-melting the uppercomponents to one another, thereby affecting elasticity in various areasas desired.

FIGS. 6 and 7 show another embodiment of an article of footwear 112 witha midsole assembly 110 having many of the same components as the midsoleassembly 10. Identical reference numbers are used for componentsidentical to those shown and described with respect to FIGS. 1-5. Forexample, the bladder element 16 is the same as previously described. Afirst resilient midsole layer 114 is similar to first resilient midsolelayer 14 but has upwardly-extending protrusion 174A in the heel regionand upwardly-extending protrusion 174B in the forefoot region, both ofwhich are visible through the substantially transparent bladder element16 from the exterior of the article of footwear 112 as indicated in FIG.7. The first resilient midsole layer 114 has laterally-extending grooves185 on a bottom surface 184, and no outsole elements. Only some of thegrooves 185 are indicated in FIG. 7. A relatively large groove 187extends laterally across the forefoot region to promote flexibility ofthe first resilient midsole layer 114 in the forefoot region.

As is apparent in FIGS. 6 and 7, when inflated, the bladder element 16is configured with a base surface 190 (also referred to as a baseportion) that rests on the first resilient midsole layer 114. The firstresilient midsole layer 114 is configured with a medial side recess 144Aand a lateral side recess 144B a portion of which is visible in FIG. 6.The recesses 144A, 144B are configured to receive the medial arm portion26A and the lateral arm portion 26B, respectively. The bladder element16 is configured to taper from the base surface 190 to a peak 192extending along the upper portion of the bladder element 16 opposite thefirst resilient midsole layer 114. The peak 192 is also illustrated inFIG. 16. The peak 192 separates the outer surface of the bladder element16 between the generally outward-facing side surface 82 that extendsbetween the base surface 190 and the peak 192, and the generallyinward-facing side surface 80 that extends between the base surface 190and the peak 192.

The second resilient midsole layer 118 is configured with a lowersurface 156 facing generally downward that has a medial side recess 166Aand a lateral side recess 166B with a central raised portion 140extending generally downward and partially defining the side recesses166A, 166B. The second resilient midsole layer 118 is configuredcooperatively with the first resilient midsole layer 114 and the bladderelement 16 so that the second resilient midsole layer 118 is supportedsubstantially on the inward-facing surface 80 of the bladder element 16,enabling a large portion of the outward-facing surface 82 to be exposed.When the first resilient midsole layer 114, the bladder element 16, andthe second resilient midsole layer 118 are assembled in this manner andsecured to one another such as by adhesives, a sealed internal chamber120 is formed that is at ambient pressure. Either or both of the firstresilient midsole layer 114 and the second resilient midsole layer 118can have recesses opening to the internal chamber 120 or covered by theother of the foam layers 114, 118 to create internal ambient pods toaffect flexibility and ride. For example, FIG. 7 shows that the firstresilient midsole layer 114 has a recess 174C in the forefoot region.During engagement of the article of footwear 112 with the ground planeand under sufficient loading force of at least a threshold minimumloading force, the second resilient midsole layer 118 may contact theprotrusion 174B such that the recess 174C may be closed off from theinternal chamber 120, and thereby function as a separate embodiment podaffecting cushioning and ride of the article of footwear 112. The secondresilient midsole layer 118 may contact the protrusion 174A in a similarmanner to close off the portion of chamber 120 forward of the protrusion174A from the portion rearward of the protrusion 174A.

A footwear upper 131 is secured to the second resilient midsole layer118 by any suitable manner, such as adhesives, stitching, a combinationof these methods, or otherwise. In the embodiment shown, the upper 131is adhered to an upward extending flange 133 that extends around aperimeter of the second resilient midsole layer 118. As shown in FIG. 7,the flange 133 is exposed on the article of footwear 112. A strobel unit132 is adhered to the upper 131 and overlays and is adhered to the uppersurface 154 of the second resilient midsole layer 118. The footwearupper 131 may include multiple textile layers hot-melted together withTPU or polymer foam. A fabric net can also be integrated in the upper131, and stretched as desired prior to hot-melting the upper componentsto one another, thereby affecting elasticity in various areas asdesired.

FIG. 8 is a flow diagram of one method of manufacturing 200 the articleof footwear 12 of FIGS. 1-5 or the article of footwear 112 of FIGS. 6-7.The method 200 includes supporting a bladder element 16 at theperipheral region of the first resilient midsole layer 14 or 114 in step202. Step 202 may include placing the medial and lateral arms portions26A, 26B in the side recesses 44A, 44B, and the heel portion 24 at theheel region 28 of the first resilient midsole layer 14 or 114.Optionally, the method 200 may also include forming the bladder element16, such as by thermoforming or by any other suitable method, andinflating the bladder element. Manufacturing the bladder element may beaccording to the method of manufacturing 800 described herein withrespect to FIGS. 17, 18 and 21. Alternatively, manufacturing of thebladder element 16 can be accomplished separately, and the method 200can be accomplished using a pre-manufactured bladder element that isprovided prior to the method 200.

The method 200 also includes supporting the second resilient midsolelayer 18 or 118 on the bladder element 16. Step 204 may include placingthe medial and lateral arm portions 26A, 26B in the side recesses 66A,66B of second resilient midsole layer 18 or side recesses 166A, 166B ofsecond resilient midsole layer 118, and the heel portion 24 in the heelrecess 71.

With the bladder element 16 arranged between the first resilient midsolelayer 14 or 114 and the second resilient midsole layer 18 or 118 in thismanner, the first and second resilient midsole layers 14 or 114 and 18or 188 are secured to the bladder element 16 in step 206 to seal theinternal chamber 20 or 120.

Securing the bladder element 16 to the first resilient midsole layer 14or 114 in step 206 may include sub-step 208, in which the base surface190 of the bladder element 16 is secured to the first resilient midsolelayer 14 by adhesives. Step 206 may also include sub-step 210, in whichthe second resilient midsole layer 18 or 118 is secured to the bladderelement 16 by adhesives, with the second resilient midsole layer 18 or118 being positioned substantially at the inward facing surface 80,inward of the peak 192. The method 200 includes step 212 in which thefootwear upper 131 and strobel unit 132 are secured to the secondresilient midsole layer 18 or 118, such as by adhesives, stitching, orboth.

FIGS. 9 and 10 show another embodiment of a midsole assembly 310 for anarticle of footwear 312. The midsole assembly 310 and article offootwear 312 are alike in all aspects to the midsole assembly 110 andarticle of footwear 112 except that the overlaying component is both afootwear upper 331 and strobel unit 337 with a second resilient midsolelayer 318 to which the footwear upper 331 is double-lasted. The footwearupper 331 surrounds the sides 333 of the second resilient midsole layer318 as well as the bottom surface 356 of the second resilient midsolelayer 318. The upper 331 and strobel unit 337 may be secured to thesecond resilient midsole layer 318 by adhesive, heat fusing or by anyother suitable manner.

As is apparent in FIG. 10, the second resilient midsole layer 318 isthus completely concealed at the exterior of the article of footwear 312by the upper 331. The upper 331 rather than the second resilient midsolelayer 318 is in direct contact with the bladder element 16. The bottomportion of the upper 331 at the underside of the second resilientmidsole layer 318 is visible through the bladder 16 from the lateral andmedial sides of the article of footwear 312.

FIG. 11 is a flow diagram of one method of manufacturing 400 the articleof footwear 312 of FIGS. 9-10. The method 400 includes securing thefootwear upper 331 to the second resilient midsole layer 318 in step402, and in step 404, securing a strobel unit 337 to the secondresilient midsole layer 318 at the upper surface 354 of the secondresilient midsole layer 318. Alternatively, the upper 331 can be securedto the upper surface 354, and a separate upper layer can be secured tothe side 333 and bottom surface 356. In either case, securing can be byadhesives, heat fusing, or the like.

The bladder element 16 is then supported at the peripheral region of thefirst resilient midsole layer 114 in step 406. Step 406 may includeplacing the medial and lateral arms portions 26A, 26B in the siderecesses 44A, 44B, and the heel portion 24 at the heel region 28 of thefirst resilient midsole layer 114. Optionally, the method 400 may alsoinclude forming the bladder element 16, such as by thermoforming or byany other suitable method, and inflating the bladder element.Additionally, the bladder element 16 may be manufactured according tothe method of manufacturing 800 described herein with respect to FIGS.17, 18 and 21. Alternatively, manufacturing of the bladder element 16can be accomplished separately, and the method 400 can be accomplishedusing a pre-manufactured bladder element that is provided prior to themethod 400.

The method 400 also includes step 408, supporting the upper 331 with thesecond resilient midsole layer 318 attached thereto as set forth insteps 402 and 404, on the bladder element 16. Step 408 may includeplacing the medial and lateral arm portions 26A, 26B in side recesses366A, 366B that run along the peripheral region of the second resilientmidsole layer 318 similar to recesses 66A, 66B of FIG. 3, and the heelportion 28 in a recess similar to recess 71 of FIG. 3.

With the bladder element 16 arranged between the first resilient midsolelayer 114 and the second resilient midsole layer 318 in this manner, thefirst resilient midsole layer 114 and the second resilient midsole layer318 with upper 331 attached thereto are secured to the bladder element16 in step 410 to seal the internal chamber 120.

Securing the bladder element 16 to the first resilient midsole layer 114may include sub-step 412, in which the base portion 40 of the bladderelement 16 is secured to the first resilient midsole layer 114 byadhesive, heat fusing, or any other suitable manner. Step 410 may alsoinclude sub-step 414, in which the second resilient midsole layer 318with attached upper 331 is secured to the bladder element 16 byadhesives, heat-fusing, or other suitable manner, with the secondresilient midsole layer 318 being positioned substantially at the inwardfacing surface 80, inward of the peak 192.

FIGS. 13 and 14 show another embodiment of a midsole assembly 510 for anarticle of footwear 512. The midsole assembly 510 and article offootwear 512 are alike in many aspects to the midsole assembly 110 andarticle of footwear 112. Identical components are indicated withidentical reference numbers and are as described with respect to FIGS.6-7. The midsole assembly 510 has the same bladder element 16 and firstresilient midsole layer 114. The midsole assembly 510 does not have asecond resilient midsole layer like second resilient midsole layer 118.Instead, a rim 518 functions as an overlaying component. As shown inFIG. 12, the rim 518 extends along the entire bladder element 16 at anupper extent, and is secured to the bladder element 16 substantially onthe inward-facing surface 80. The rim 518 extends generally along thepeak 192 from the terminal ends 48A, 48B and around the heel portion 24and functions as a perch to which a footwear upper 531 is secured. Therim 518 can be any suitable material that can be secured to the bladderelement 16 and to the footwear upper 531. In one embodiment, the rim 518is thermoplastic polyurethane (TPU) and is co-molded with the bladderelement 16 as further described herein with respect to FIGS. 19-21.

The rim 518 has an upwardly-extending flange 533 that functions as acage or outer rail to provide side support for the footwear upper 531.The footwear upper 531 is attached to a generally upward-facing interiorsurface 535 of the rim 518, inward of the flange 533, so that the rim518 separates the footwear upper 531 from the bladder element 16 and anexterior surface 537 of the flange 533 is exposed.

The footwear upper 531 may be attached by any suitable method, such asby adhesives. The rim 518 may be substantially transparent. Accordingly,with the substantially transparent bladder element 16 and substantiallytransparent rim 518, the footwear upper 531 and the internal chamber 120are exposed and visible from an exterior of the article of footwear 512.An insole (not shown) can be placed in and stitched or adhered to theupper 531. The footwear upper 531 may include multiple textile layershot-melted together with TPU or polymer foam. A fabric net can also beintegrated in the upper 531, and stretched as desired prior tohot-melting the upper components to one another, thereby affectingelasticity in various areas as desired.

FIG. 15 is a flow diagram of one method of manufacturing 600 the articleof footwear 512 of FIGS. 12-14. The method 600 may include co-moldingthe rim 518 with the bladder element 16 in step 602. The bladder element16 may be manufactured according to the method of manufacturing 900described herein with respect to FIGS. 19, 20, and 22. Alternatively,manufacturing of the bladder element 16 with the co-molded rim 518 canbe accomplished separately, and the method 600 can be accomplished usinga pre-manufactured bladder element 16 with co-molded rim 518 that isprovided prior to the method 600.

The bladder element 16 with co-molded rim 518 is then supported at theperipheral region of the first resilient midsole layer 114 in step 604.Step 604 may include placing the medial and lateral arms portions 26A,26B in the side recesses 44A, 44B, and the heel portion 24 at the heelregion 28 of the first resilient midsole layer 114.

The method includes step 606, securing the bladder element 16 to thefirst resilient midsole layer 114, such as by adhesive or heat fusing.The method 600 also includes step 608, securing the footwear upper 531to the rim 518 such as by adhesive. With the footwear upper 531 and thefirst resilient midsole layer 114 secured to the bladder element 16, theinternal chamber 120 is bounded by and sealed between the upper 531, therim 518, the bladder 16, and the first resilient midsole layer 114.

The unique shape of the bladder element 16 enables efficientmanufacturing with the potential for material and time savings. As shownin FIGS. 17-19, portions of adjacent mold cavities can be nestedtogether, enabling molding of multiple bladder elements 16 in a singlemold assembly. Specifically, FIGS. 17-18 show a mold assembly 700 thatincludes a first mold portion 702 and a second mold portion 704configured for simultaneous thermoforming of multiple bladder elements,reducing scrap of the material used for thermoforming the bladderelements 16. Although the mold assembly 700 illustrates only four moldcavity portions 702, 704, 706, 708, the mold assembly 700 may beconfigured with additional nested pairs of mold cavity portionsdepending on the size of the sheet material that is thermoformed. Thefirst mold portion 702 defines a first mold cavity portion 706 and asecond mold cavity portion 708. Additionally, the first mold portion 702defines a third mold cavity portion 710 and a fourth mold cavity portion712. Each mold cavity portion 706, 708, 710, and 712 has a substantiallyarc-shaped heel cavity portion 714, a lateral arm cavity portion 716,and a medial arm cavity portion 718. The lateral arm cavity portion 716and the medial arm cavity portion 718 each extend from and arecontinuous with the respective heel cavity portion 714. The first moldcavity portion 706 and the second mold cavity portion 708 are each for abladder element 16 to be used in an article of footwear having a rightfoot orientation, as the medial arm cavity portion 718 extends from theleft side of the heel cavity portion 714 when viewed with the arm cavityportions 716, 718 extending upward from the heel cavity portion 714. Thethird mold cavity 710 and the fourth mold cavity 712 are each for abladder elements 16 to be used in an article of footwear having a leftfoot orientation, as the medial arm cavity portion 718 extends from theright side of the heel cavity portion 714 when viewed with the armcavity portions 716, 718 extending upward from the heel cavity portion714. FIG. 16 shows four bladder element 16 supported on the first moldportion 702 after thermoforming in the mold assembly 700.

When arranged as shown in FIG. 17, the medial arm cavity portion 718 ofthe first mold cavity 706 is between the lateral arm cavity portion 716and medial arm cavity portion 718 of the second mold cavity 708 andextends generally toward the heel portion 714 of the second mold cavity708. The medial arm cavity portion 718 of the second mold cavity 708 isbetween the lateral arm cavity portion 716 and medial arm cavity portion718 of the first mold cavity 706 and extends generally toward the heelportion 714 of the first mold cavity 706. Similarly, the medial armcavity portion 718 of the third mold cavity 710 is between the lateralarm cavity portion 716 and the medial arm cavity portion 718 of thefourth mold cavity 712. The lateral arm cavity portion 716 of the secondmold cavity 708 is adjacent the lateral arm cavity portion 716 of thethird mold cavity 710.

As discussed with respect to FIGS. 16 and 18, polymeric sheet materialmay be used to form the bladder elements 16, and may be laid over thefirst mold portion 702 across the mold cavity portions 706, 708, 710,712 during the formation process. A portion of the sheet material 750,752 extending between the arm portions 716, 718 of the first mold cavity706 is thus utilized in forming the medial arm portion of a secondbladder element 16 via the inter-disposed medial arm portion 718 of thesecond mold cavity 710. As best indicated in FIG. 16, which shows theresulting bladder elements 16 still in the mold cavities of the firstmold portion 702, the curvature of the inner edge 722A of the medial armportions 718 of the bladder element 16 formed in the first mold cavity706 follows the curvature of the inner edge 722B of the medial armportion of the bladder element 16 formed in the second mold cavity 708when the heel portion portion 714 of the first mold cavity 706 isdisposed at a first end 726 of the first mold portion 702 and the heelcavity portion 714 of the second mold cavity 708 is disposed at anopposite second end 728 of the first mold portion 702 as shown.Likewise, the curvature 724A of the inner edge of the medial arm portion718 of the bladder element 16 formed in the third mold cavity 710follows the curvature 724B of the inner edge of the medial arm portion718 of the bladder element 16 formed in the fourth mold cavity 712 whenthe heel cavity portion 714 of the third mold cavity 710 is disposed atthe first end 726 and the heel cavity portion 714 of the fourth moldcavity 712 is disposed at an opposite second end 728 of the first moldportion 702 as shown.

When arranged in this manner, a first distance D1 from an outer edge ofthe lateral arm cavity portion 716 of the first mold cavity 706 to anouter edge of the lateral arm cavity portion 716 of the second moldcavity 708 is less than twice a second distance D2 from an outer edge ofthe medial arm cavity portion 718 of the first mold cavity 706 to anouter edge of the lateral arm cavity portion 716 of the first moldcavity 706. The first distance D1 and the second distance D2 aredetermined along a common cross-section extending across the medial andlateral arm cavity portions of the first and second mold cavities, asbest indicated in FIG. 18. A third distance D3 from an outer edge of thelateral arm cavity portion 716 of the third mold cavity 710 to an outeredge of the lateral arm cavity portion 716 of the fourth mold cavity 712is less than twice a fourth distance D4 from an outer edge of the medialarm cavity portion 718 of the third mold cavity 710 to an outer edge ofthe lateral arm cavity portion 716 of the third mold cavity 710. Thethird distance D3 and the fourth distance D4 are determined along acommon cross-section extending across the medial and lateral arm cavityportions 716, 718 of the third and fourth mold cavities 710, 712. Thefirst and second distances D1, D2 may be the same as the third andfourth distances D3, D4 if the bladder elements 16 are all of identicalsize.

FIGS. 17 and 18 show that the second mold portion 704 has mold cavityportions 730, 732, 734, 736 configured to correspond with thesubstantially arc-shaped heel cavity portions, the lateral arm cavityportions, and the medial arm cavity portions of the first, second,third, and fourth mold cavity portions 706, 708, 710, 712 of the firstmold portion 702 when the second mold portion 704 is placed adjacent tothe first mold portion 702 as shown in FIG. 18. The mold cavities of thefirst and second mold portions 702, 704 together define molds for thefirst, second, third, and fourth bladder elements 16 shown from left toright in FIG. 16 each having a substantially arc-shaped heel portion 24,a lateral arm portion 26B, and a medial arm portion 26A, with thelateral arm portion 26B and the medial arm portion 26A each extendingfrom the substantially arc-shaped heel portion 24, and providing thepeak 192, and base surface 190 such as shown and described with respectto FIG. 7.

FIG. 18 shows the mold cavities of the mold cavity portions 702, 704aligned for simultaneous formation of the first, second, third andfourth bladder elements 16 of FIG. 16. The bladder elements 16 can beformed by any suitable process, such as thermoforming a first polymericsheet 750 and a second polymeric sheet 752 as described in U.S. Pat. No.6,082,025 to Bonk et al., which is hereby incorporated by reference inits entirety. The first and second sheets 750, 752 are originallyplanar, but take on the shapes of the mold cavities via vacuuming andheating steps included in the thermoforming process. The bladderelements 16 can then be cooled, inflated to a predetermined pressure,and sealed to retain pressure. Various thermoforming techniques may beused, such as are described in U.S. Pat. No. 6,119,371 to Goodwin etal., which is hereby incorporated by reference. The pressure and heatbetween the mold portions 702, 704 will cause the sheets to bond to oneanother in the areas between the arm portions. Excess material is thenremoved by trimming. A molded flange 747 around each of the bladderelements 16 can then be trimmed at an inner edge 749 so that the firstbladder element 16 has a relatively small perimeter flange 751 (shown,e.g., in FIG. 6) at which the sheets 750, 752 are bonded to one another.Trimming may be automated and may occur at a separate steel roll dietrim. Alternatively, trimming could be accomplished manually.

FIG. 19 shows an alternate mold assembly 700A that has an identicalfirst mold portion 702 to mold assembly 700, but utilizes a second moldportion 704A that has a rim portion 756 extending from each mold cavityportion 730, 732, 734, 736. The rim portion 756 extends along the entiremold cavity portion as indicated with respect to mold cavity portion 730in FIG. 20. The rim portion 756 is filled with a TPU material to form arim 518 shown in FIGS. 12 and 13. The TPU material can be placed in therim portion 756 and co-molded with the first sheet 750 and second sheet752 so that the rim portions 756 are integral with the bladder elements16.

FIG. 21 is a flow diagram of a method of manufacturing 800 the bladderelements of FIGS. 16 and 18 using the mold assembly 700. Under themethod 800, materials for the bladder elements 16 are provided at themold assembly 700 in step 802. Step 802 may include placing sheets ofmaterial 750, 752 in the mold assembly 700. The first, second, third,and fourth bladder elements 16 are then formed in step 804, with thefirst bladder elements 16 being formed in mold cavity portions 706 and730, the second bladder elements 16 being formed in mold cavity portions708 and 732, the third bladder element 16 being formed in mold cavityportions 710, 734, and the fourth bladder element 16 being formed inmold cavity portions 712, 736. The forming step 804 may includethermoforming by heating the sheets of material 750, 752, providingvacuum to urge the sheets to the shape of the mold cavities, andsubsequently inflating and sealing the bladder elements 16. In step 806,excess sheet material is trimmed, such as at cut lines 760, so that asmall flange borders the perimeter of the bladder element, similar tothe flange 751 shown in FIG. 6. The trimming may occur after removal ofthe sheets 750, 752 from the mold assembly 700. The sheets 750, 752 willbe bonded together in the areas between the mold cavities portions 706and 730, 708 and 732, 710, 734, and 712, and 736 due to the compressionof the mold assembly 700 and thermoforming of the materials.

FIG. 22 is a flow diagram of a method of manufacturing 900 the bladderelements of FIGS. 12, 13 and 19 using the mold assembly 700A. Under themethod 900, material for the rim 518 is provided at the mold assembly700A in step 902, and material for the bladder elements 16 is providedat the mold assembly 700A in step 904. Step 902 may include placing therim material in the rim cavity portion 756 of the mold portion 704A.Step 904 may include placing sheets of material 750, 752 in the moldassembly 700A. The first, second, third, and fourth bladder elements 16are then formed, in step 906 with the first bladder elements 16 beingformed in mold cavity portions 706 and 730, the second bladder element16 being formed in mold cavity portions 708 and 732, the third bladderelement 16 being formed in mold cavity portions 710, 734, and the fourthbladder element 16 being formed in mold cavity portions 712, 736. Theforming step 906 may include thermoforming by heating the sheets ofmaterial 750, 752, providing vacuum to urge the sheets to the shape ofthe mold cavities, and subsequently inflating and sealing the bladderelements 16. The rims are co-molded to the bladder elements 16 in step908. Step 908 can occur prior to or simultaneously with step 906. Instep 910, excess sheet material is trimmed, such as at cut lines 760, sothat a small flange borders the perimeter of the bladder element,similar to the flange 751 indicated in FIG. 6. The trimming may occurafter removal of the sheets 750, 752 from the mold assembly 700A. Thesheets 750, 752 will be bonded together in the areas between the moldcavity portions 730 and 732, and between the mold cavity portions 734and 736, due to the compression of the mold assembly 700A andthermoforming of the materials.

Referring to FIGS. 23-27, a midsole assembly 1010 and an outsole 1086are shown in exploded view. The midsole assembly 1010 includes thefluid-filled bladder element 16 as described with respect to FIG. 1.When assembled, the midsole assembly 1010 and the outsole 1086 form thesole assembly of an article of footwear 1012 of FIG. 25. The bladderelement 16 is arranged so that the substantially arc-shaped heel portion24 is positioned in a heel region 28 of the article of footwear 1012,and the arm portions 26A, 26B extend from the heel region 28 to theforefoot region 30 along a peripheral region 22. The article of footwear1012 has a heel region 28, a forefoot region 30, and a midfoot region 32corresponding with portions of a human foot as described with respect tosimilar regions of the midsole layer 14 of FIG. 2.

The midsole assembly 1010 includes a resilient midsole layer 1018 thatis secured to and rests on the bladder element 16 as shown in FIG. 25.The midsole layer 1018 has a large number of protrusions 1021 thatdescend from a lower portion of the midsole layer 1018 into a cavity1023 between the arm portions 26A, 26B. An outsole layer or outsoleelements, such as an outsole layer 1086, is secured to the bladderelement 16 as well as to a lowest extent 1025 of the protrusions 1021.The outsole layer 1086 can be a unitary layer that extends beneath andis secured to the bladder element 16 as well as to the protrusions 1021,or can be discrete outsole elements on a lower surface of the bladderelement 16 and on each protrusion 1021. The outsole layer 1086 can be amaterial similar to the midsole layer 1018, a rubber material, or can bea unisole material. For example, if the outsole layer 1086 is a materialsimilar to the midsole layer 1018, such as but not limited to foam, suchas an EVA foam, then the outsole layer 1086 may function as anothermidsole layer, and additional outsole elements can be secured to abottom surface thereof. The outsole layer 1086 can also be referred toas an additional sole layer, or an outer foam layer, and the midsolelayer 1018 can be referred to as an inner foam layer.

The midsole layer 1018 is configured so that the lowest extent 1025 ofeach of the protrusions 1021 terminates above the base surface 190 ofthe bladder element 16 in the absence of at least the threshold loadingforce acting to compress the midsole layer 1018. A distance D5 spacesthe lowest extent 1028 of the outsole layer 1086 secured to theprotrusions 1021 from a lowest extent 1027 of the outsole layer 1086where secured to the bladder element 16. The distance D5 thus alsorepresents the distance of the lowest extent 1028 of the outsole layer1086 from the ground plane G. The lowest extent 1028 of the outsolelayer 1086 is the bottom surface of the outsole layer 1086 at theprotrusions 1021. With this configuration, the protrusions 1021 are notin operative contact with the ground plane G in the absence of at leastthe threshold loading force on the midsole layer 1018, as represented bya compressive downward loading force F shown in FIG. 26. As used herein,the protrusions 1021 are in “operative contact” with the ground plane Gwhen the protrusions 1021 directly contact the ground plane G if nooutsole layer 1086 is provided. In other words, the protrusions 1021 arenot in operative contact with the ground plane G until a loading force Fis applied that is at least a predetermined threshold loading force thatis sufficient to cause the lowest extent 1028 of the extension portions1029 of the outsole layer 1086 to contact the ground plane G, with theextension portions 1029 thus becoming part of the ground contact surfaceof the article of footwear 1012. If additional outsole elements, such asoutsole layer 1086, are secured to the protrusions 1021, then theprotrusions are in operative contact with the ground plane G when theportion of the outsole layer 1086 secured to the protrusions 1021contacts the ground plane G so that the protrusions 1021 are thus inindirect contact with the ground plane G.

As best shown in FIGS. 24 and 27, the outsole layer 1086 is secured tothe entire base surface 190 of the bladder element 16. The outsole layer1086 has a peripheral portion 1030 and extension portions 1029 thatextend inward and slightly upward from the peripheral portion 1030 tointerface with the lowest extent 1025 of each protrusion 1021. Theoutsole layer 1086 is secured to the bladder element 16 at theperipheral portion 1030, and the protrusions 1021 are secured to theextension portions 1029 by bonding, adhesives, welding, or the like.

A flex groove 1033 is formed in and extends generally lengthwise acrossa bottom surface of the midsole layer 1018 from the forefoot region 30to the heel region 28 between different ones of the protrusions 1021.Additional grooves 1041 extend generally laterally between theprotrusions 1021. A footwear upper 1031 is welded, adhered, stitched, orotherwise secured to the midsole layer 1018.

As best shown in FIGS. 25 and 26, the resilient midsole layer 1018 andthe bladder element 16 are configured so that a first portion 1057 ofthe resilient midsole layer 1018 adjacent the inward-facing surface 80of the bladder element 16 is secured to the bladder element 16 such asby welding, bonding, or the like. A second portion 1059 of the resilientmidsole layer 1018 adjacent the inward-facing surface 80 of the bladderelement is spaced from the bladder element 16 when the thresholdcompressive force F is not applied to the resilient midsole layer 1018.In other words, as shown in FIG. 25, the second portion 1059 of eachprotrusion 1021 is spaced from the inward-facing surface 80 of thebladder element 16. The spacing of the second portions 1059 is due tothe angling of the second portions 1059 inward toward the center of themidsole layer 1018 (i.e., toward the flex groove 1033) relative to thefirst portion 1057. The second portion 1059 has a surface profile 1061Athat is substantially identical to a surface profile 1061B of theportion of the inward-facing surface 80 of the bladder element 16 thatis adjacent to the second portion 1059.

Due to the flexible and resilient properties of the midsole layer 1018,under the threshold loading force F, compression of the midsole layer1018 as well as flexing at the flex groove 1033 causes the secondportions 1059 to move into contact with the inward-facing surface 80 ofthe bladder element 16, as shown in FIG. 26. During application of theforce F, a first stage of attenuation of the force F occurs prior tooperative contact of the protrusions 1021 with the ground plane G. Thatis, the first stage of attenuation occurs before the extension portion1029 of the outsole layer 1086 contacts the ground plane G. During thefirst stage of attenuation, the midsole layer 1018 compresses downwardto attenuate some of the loading force F. A second stage of attenuationoccurs after the protrusions 1021 are in operative contact with theground plane G through the extension portions 1029 of the outsole layer1086, as shown in FIG. 26. In the first stage, compression and flexingof the midsole layer 1018 has caused some or all of the second portions1059 to come into contact with the inward-facing surface 80 of thebladder element 16. During the second stage, the protrusions 1021 havemoved into operative contact with the ground plane G, so that theloading force F is attenuated both by the protrusions 1021, and by thebladder element 16.

The midsole assembly 1010 can be tuned during the design of the assembly1010 to provide a desired underfoot feel by selecting the spacing of theportions 1059 from the bladder element 16, the profile 1061A, thedistance D5, the depth and width of the flex groove 1033, and theselection of material for the midsole layer 1018. For example, thesevariables may be selected so that the protrusions 1021 move intooperative contact with the ground surface G under at least the thresholdloading force F only after the second portion 1059 of the resilientmidsole layer 1018 moves into contact with the inward-facing surface 80of the bladder element 16. The midsole assembly 1010 can thus provide afirst stage of attenuation of loading force when the second portion 1059of the resilient midsole layer 1018 moves into contact with theinward-facing surface 80 of the bladder element, and a second stage ofattenuation of loading force F when the protrusions 1021 thereafter moveinto operative contact with the ground surface G. Selecting thevariables described can cause the first stage of attenuation to have afirst energy absorbing characteristic, and the second stage ofattenuation to have a second energy absorbing characteristic. Forexample, the rate of compression of the midsole assembly 1010 may bedifferent in the different stages of attenuation. Additionally, when theprotrusions 1021 contact the ground, a greater tactile underfoot feel isexperienced by a wearer of the article of footwear 1012, which may bedesirable.

FIG. 28 shows a flow diagram of one method 1100 of manufacturing thearticle of footwear 1012 of FIGS. 23-27 with the midsole assembly 1010.The method 1100 begins in step 1110 by providing a bladder element 16formed from first and second polymeric sheets so that the bladderelement 16 has a substantially arc-shaped heel portion 24, a lateral armportion 26B, a medial arm portion 26A laterally-spaced from the lateralarm portion 26B, and with the lateral arm portion and the medial armportion each extending from the heel portion 24. Providing the bladderelement 16 in step 1110 may also include forming the bladder element 16in step 1120, as described with respect to FIGS. 17 and 18.Alternatively, the bladder element 16 can be obtained after it has beenformed.

The method 1100 further includes step 1130 in which the midsole layer1018 with the descending protrusions 1021 and the flex groove 1033 isprovided. In step 1140, the midsole layer 1018 is positioned relative tothe bladder element 16 so that the protrusions 1021 descend between thearm portions 26A and 26B into the cavity 1023. The midsole layer 1018 isthen secured to the bladder element 16 in step 1150. As discussed withrespect to FIG. 25, only a first portion 1057 of the midsole layer 1018facing the inward-facing surface 80 of the bladder element 16 is securedto the bladder element 16. Optionally, in step 1160, an additional solelayer, such as outsole layer 1086, is secured to the bladder element 16and, optionally, to the protrusions 1021. In step 1170, the footwearupper 1031 is secured to the midsole layer 1018 by any suitable mannersuch as disclosed herein.

Referring now to FIGS. 29-31, alternate embodiments of bladder elements1216, 1316, and 1416 are illustrated. Each of the bladder elements 1216,1316, 1416 has a substantially arc shaped heel portion 24, a laterallateral arm portion 26B, and a medial arm portion 26A spaced from thelateral arm portion 26B to form a generally peripheral chamber. Each ofthe arm portions 26A, 26B extends from a heel region 28 to a forefootregion 30, and are arranged generally at a peripheral region 22 thatrespectively correspond with a heel region, a forefoot region, and aperipheral region of an article of footwear in which the bladder element1216, 1316, or 1416 is assembled.

Each of the bladder elements 1216, 1316, and 1416, is formed from anupper polymeric sheet and a lower polymeric sheet of any of thematerials as described with respect to bladder element 16. The armportions 26A, 26B are interconnected in the forefoot region 30 by a webformed by the respective bladder element 1216, 1316, or 1416. In otherwords, the polymeric sheets are trimmed in the area between the armportions 26A, 26B only at the heel region 28, creating an opening 1267,1367, 1467, through the respective bladder element 1216, 1316, 1416, toprovide a cavity similar to cavity 1023 in FIG. 23. The polymeric sheetsare not trimmed in the area between the arm portions 26A, 26B at theforefoot region 30.

Specifically, with reference to the bladder element 1216 of FIG. 29, aweb 1260 connects the arm portions 26A, 26B and extends from a rearwardend 1261 in the midfoot region 32 to a distal end 1263 of the forefootregion 30. The web 1260 includes areas where the adjacent upper andlower sheets are compressed together. These areas are indicated withreference number 1262. Portions of the compressed area 1262 formthickened flanges adjacent the arm portions 26A, 26B and heel portion24. An inner flange 1264 is at an inward-facing surface 1280 shown inFIG. 33. An outer flange 1265 is at an outward-facing surface 1282 ofthe bladder element 1216. The web 1260 also includes descendingprotrusions in the form of fluid-filled pods 1266A, 1266B, 1266C, 1266Dmade discreet and separated from the arm portions 26A, 26B and heelportion 24 by the compressed portions 1262.

The fluid-filled pods 1266A, 1266B, 1266C, 1266D are preferably filledwith air at ambient pressure. The pods 1266A, 1266B, 1266C, 1266D may beformed during thermoforming of the bladder element 1216 by providingmold assemblies that enable the lower polymeric sheet 1252 to beseparated from the upper polymeric sheet 1250 and formed into thedesired pod shapes. For example, FIG. 36 shows an article of footwear1212 that includes the bladder element 1216 and indicates therelationship between the upper sheet 1250 and the lower sheet 1252 at across-section through the forefoot region 30 indicated in FIG. 29. Thesheets 1250, 1252 are separated from one another at the arm portions26A, 26B and at the fluid filled pods 1266A, 1266B, 1266C, 1266D but arebonded to one another at compressed areas 1262. As shown in FIGS. 35 and36, the pods, such as pod 1266C, are formed to extend generallydownward, and are not in operative contact with a ground surface in theabsence of a sufficient loading force F. The pods 1266C will move intooperative contact with the ground surface G under the sufficient loadingforce F to thereby function similarly as the protrusions 1021 of FIG.25.

Downward protrusion of the pods 1266 is enabled by bonding the sheets1250, 1252 via a roll seam at an inward-facing flange 1264 of the armportions 26A, 26B. The flange 1264 and the seam therein progressesgenerally upward from the heel region 24 to the forefoot region 30 alongthe arm portions 26A, 26B. Such a roll seam is further shown andexplained with respect to FIG. 32. The outer flange 1265 is provided bya pinch seam. The outer flange 1265 is at a lower portion of the bladderelement 1216 from the heel region 28 to the forefoot region 30, and doesnot roll or progress upward like the inner flange 1264.

Additional sole layer 1214 can be secured to the lower sheet 1252 toprovide additional cushioning response and support for the downwardextending pods such as pod 1266C shown in FIG. 36. Specifically, thesole layer 1214 is formed with apertures 1215 that correspond with thedescending pods 1266C. The apertures 1215 are sized to provide a sleevethat generally supports the downwardly descending pods and allows alowest extent of each pod to descend below the sole layer 1214 throughthe aperture 1215. In this manner, the sole layer 1214 cups the podssuch as pod 1266C.

A midsole layer 1218 is secured to an upper portion of the bladderelement 1216. Specifically, the midsole layer 1218 has descendingprotrusions 1021 (shown in FIG. 37) like those of FIG. 23, but theprotrusions 1021 are only in the heel region 28 of the midsole layer1218 and are positioned so that the protrusions 1021 extend through anopening 1267 in the heel region 28 of the bladder element 1216. Theopening 1267 is shown in FIG. 29. As shown in FIG. 37, the midsole layer1218 has an opening 1271 in the forefoot region 30 so that the midsolelayer 1218 forms only a narrow strip 1272 around the forefoot region 30that extends over and is secured to the arm portions 26A, 26B. Afootwear upper 1231 is cupped by the strip 1272 of the midsole layer1218, and is secured to the midsole layer 1218 along the strip 1272 andin the heel region 28, and also to the upper sheet 1250 of the bladderelement 1216 in the forefoot region 30 by any suitable manner such asdisclosed herein.

As shown in FIG. 36, an outsole layer provided by discreet outsoleelements 1286 is secured to a lower surface of the peripheral bladderelement (i.e., to the underside of the arms 26A, 26B and the heelportion 24, as well as to a lower surface of each of the pods, such aspod 1266C). The outsole elements 1286 can be a material similar to thesole layer 1214, such as a material suitable for a midsole or unisole,or can be a more durable material such as a rubber material. The outsoleelements 1286 contact the ground plane G under the pods 1266C when thepods 1266C move downward under at least the threshold loading force F,similar to movement of the protrusions 1021 in FIG. 26. The midsoleassembly 1210 with upper 1231 and outsole elements 1286 form an articleof footwear 1212.

FIGS. 30 and 31 are alike in all aspects to FIG. 29, but withdifferently shaped ambient pods. Specifically, a web 1360 of bladderelement 1316 in FIG. 30 includes compressed portions 1362, including acompressed flange 1364 adjacent the arm portions 26A, 26B, an opening1367 in the heel region 28, and differently shaped ambient pods 1366B,1366C. A web 1460 of bladder element 1416 in FIG. 31 includes compressedportions 1462, including a compressed flange 1464 adjacent the armportions 26A, 26B, an opening 1467 in the heel region 28, anddifferently shaped ambient pods 1466A, 1466B, 1466C, 1466D, 1466E, and1466F. The pods 1466A, 1466B, 1466C are contiguous and form one largerpod. The pods 1466D, 1466E, and 1466F are contiguous and form anotherlarger pod. Either of the bladder elements 1316 and 1416 can be used inplace of bladder element 1216 in the midsole assembly 1210 and of FIG.36.

Referring to FIG. 38, a method of manufacturing 1500 an article offootwear with any of the bladder elements 1216, 1316, 1416 of FIGS.29-31 is shown. The method 1500 is described with respect to the articleof footwear 1212 of FIG. 36. The method 1500 includes step 1510,providing a bladder element 1216 formed from first and second polymericsheets 1250, 1252 so that the bladder element 1216 has a substantiallyarc-shaped heel portion 24, a lateral arm portion 26B, a medial armportion 26A laterally-spaced from the lateral arm portion 26B, and withthe lateral arm portion 26B and the medial arm portion 26A eachextending from the heel portion 24.

Providing the bladder element 1216 in step 1510 may include forming thebladder element 1216 in step 1520, such as by thermoforming in a moldassembly configured to enable formation of the pods 1266A, 1266B, 1266C,and 1266D. Alternatively, the bladder element 1216 can be obtained afterit has been formed. Forming the bladder element 1216 in step 1520includes sub-step 1530, in which the polymeric sheets 1250, 1252 arejoined at an inner flange 1264 by a rolled pinch seam 1253. The pinchseam 1253 is the joining of the sheets 1250, 1252 by compression at theflange 1264 at the inward-facing side of each arm portion 26A, 26B. Thepinch seam 153 progresses upward (i.e., rolls upward) along the bladderelement 1216 from a relatively low position at the heel portion 24 to arelatively high position at the top of the arm portions 26A, 26B at theforefoot region 30. The location of the pinch seam 1253 in FIGS. 32-35illustrates the progression from a low position (FIG. 33) to a highposition (FIG. 35). At the high position, the pinch seam 1253 is at thetop, or highest level, of the bladder element 1216, allowing the web1260 and arm portions 26A, 26B to provide a generally flatfoot-receiving surface in the forefoot region 30. The web 1260 extendsbetween the arm portions 26A, 26B at the cross-sections of FIGS. 34 and35. In the forefoot region 30 of FIG. 35, the web 1260 is at the highestpoint of the bladder element 1216, with the upper sheet 1250 providing asmooth, flat surface. Due to the progression of the pinch seam 1253 froma low position to a high position on the bladder element 1216, the pinchseam 1253 is also referred to as a roll seam. Progression of the seam1253 in this manner is enabled by the shapes of the mating mold portionsto create the flange 1264 in which the first and second polymeric sheets1250, 1252 are positioned and thermoformed. In other words, the moldportions are designed to create the roll pinch seam 1253 at the innerflange 1264 and pinch seam at the outer flange 1265.

Following step 1510 with sub-steps 1520 and 1530, the sole layer 1214 issecured to a lower surface of the bladder element 1216 in step 1540 withthe pods extending downward through apertures 1215 in the sole layer1214, enabling the sole layer 1214 to cup the pods, as illustrated withrespect to pod 1266C in FIG. 36. The sole layer 1214 also extends aroundand cups the remaining pods 1266A, 1266B, and 1266D as well. The solelayer 1214 can be configured to extend under the entire bladder element1216 with apertures provided for each of the pods 1266A, 1266B, 1266C,and 1266D to extend through.

Following step 1540, outsole elements 1286 can be secured to each of theexposed lower portions of the pods 1266A, 1266B, 1266C, and 1266D and tothe bladder element arm portions 26A, 26B and heel portion 24 in step1550, as shown in FIG. 36. In step 1560, an additional sole layer suchas sole layer 1218 of FIG. 37 can be secured to an upper surface of thebladder element 1216 in step 1560. In step 1570, a footwear upper 1231can then be secured to the bladder element 1216 by adhesive, stitching,or otherwise.

As an alternative to the roll pinch seam 1253 at inner flange 1264 andpinch seam of outer flange 1265, both the inner and outer flange couldinstead be located at an uppermost portion of any of the bladderelements 1216, 1316, 1416, and formed in a swept pinch seam to create acupping rim for a footwear upper. FIGS. 39-42 show such an alternativeembodiment of an article of footwear 1612 that has a midsole assembly1610 with a bladder element 1616 with arm portions and a heel portionlike that of FIG. 29, but that has a “full skin” footbed. In otherwords, webbing 1660 extends between the arm portions from the heelregion 28 to the forefoot region 30, with no trimming or cutouts.Descending ambient fluid-filled pods 1666 are formed by the upper andlower sheets 1650, 1652 by compressing the sheets together in compressedareas 1662, and separating the sheets to form the pods 1666.

The outer flange 1665 is formed with a swept pinch seam so that theflange 1665 extends generally upward, and serves as a rim to cup afootwear upper 1631 secured thereto. As shown in FIG. 42, the outerflange 1665 is exposed on the article of footwear 1612. No sole layer isprovided between the bladder element 1616 and the footwear upper 1631.By compressing the sheets into shaped areas of the mold assembly, theflange 1665 can be formed to be generally tapered, and triangular incross-section, with a thickness T1 at a base of the taper that isgreater than the sum of the thicknesses T2 and T3 of the sheets 1650,1652 away from the outer flange 1665. An inner flange 1664 is alsoformed by a swept pinch seam to extend generally level with a top of thearm portions 26A, 26B. Outsole element 1686 is secured to lower surfacesof the bladder element 1616 and lower surfaces of the pods 1666. Anadditional sole layer 1614 can be secured to the lower sheet 1652 toprovide additional cushioning response and support for the downwardextending pods such as pod 1666 shown in FIGS. 39-42. Specifically, thesole layer 1614 is formed with apertures 1615 that correspond with thedescending pods 1666. Each aperture 1615 is sized to allow a lowerextent of a pod 1666 to descend through the sole layer 1614 at theaperture. In this manner, the sole layer 1614 functions as a sleeve thatgenerally supports and cups the descending pods, such as pod 1666.

Referring to FIG. 43, a method of manufacturing 1700 an article offootwear 1612 with the bladder element 1616 of FIGS. 39-42 is shown. Themethod 1700 includes step 1710, providing a bladder element 1616 formedfrom first and second polymeric sheets 1650, 1652 so that the bladderelement 1616 has a substantially arc-shaped heel portion 24, a lateralarm portion 26B, a medial arm portion 26A laterally-spaced from thelateral arm portion, and with the lateral arm portion and the medial armportion each extending from the heel portion.

Providing the bladder element 1616 in step 1710 may include forming thebladder element 1616 in step 1720, such as by thermoforming in a moldassembly configured to enable formation of the pods 1666. Alternatively,the bladder element 1616 can be obtained after it has been formed.Forming the bladder element 1616 in step 1720 includes sub-step 1730, inwhich the polymeric sheets 1650, 1652 are joined at an outer flange 1665by a swept pinch seam 1653. The pinch seam 1653 is the joining of thesheets 1650, 1652 by compression at the flange 1665 at theoutward-facing side of each arm portion 26A, 26B. The pinch seam 1653 isat a high position at the top, or highest level, of the bladder element1616 along the entire bladder element 1616. The inner flange 1664 isalso formed by a pinch seam at an upper portion of the bladder element1216, preferably at the top of the bladder element 1616 so that the web1660 extends between the arm portions 26A, 26B at the upper portion orhighest level of the bladder element 1616 from the heel portion 24 tothe forefoot region 30, with the upper sheet 1650 providing a smooth,flat surface. Providing the flanges 1664, 1665 in this manner is enabledby the shapes of the mating mold portions in which the first and secondpolymeric sheets 1650, 1652 are positioned and thermoformed.

Following step 1710 with sub-steps 1720 and 1730, the sole layer 1614 issecured to a lower surface of the bladder element 1616 in step 1740 withthe pods 1666 extending downward through apertures 1615 in the solelayer 1614, enabling the sole layer 1614 to cup the pods 1666, asillustrated in FIG. 39. The sole layer 1614 can be configured to extendunder the entire bladder element 1616 with apertures provided for eachof the pods 1666 to extend through. Following step 1740, outsoleelements 1686 can be secured to each of the exposed lower portions ofthe pods 1666 and to the bladder element arm portions 26A, 26B and heelportion 24 in step 1750, as shown in FIGS. 39-42. In step 1760, afootwear upper 1631 can then be secured to the bladder element 1616 byadhesive, stitching, or otherwise.

Referring to FIGS. 44-47, a portion of an article of footwear 1812 isshown that includes a midsole assembly 1810 with a fluid-filled bladderelement 16 as described with respect to FIG. 1. The bladder element 16is arranged so that the substantially arc-shaped heel portion 24 ispositioned in a heel region 28 of the article of footwear 1812, and thearm portions 26A, 26B extend from the heel region 28 to the forefootregion 30 along a peripheral region 22. The article of footwear 1812 hasa heel region 28, a forefoot region 30, and a midfoot region 32corresponding with portions of a human foot as described with respect tosimilar regions of the midsole layer 14 of FIG. 2.

The midsole assembly 1810 includes a resilient midsole layer 1818 thatis secured to and rests on the bladder element 16 as shown in FIGS. 45and 46. The midsole layer 1818 has protrusions 1821 that descend from alower portion of the midsole layer 1818 into a cavity 1823 between thearm portions 26A, 26B. The midsole layer 1818 may be referred to as aninner foam layer as it extends inward of the bladder element 16. Anadditional sole layer 1886, which may be referred to as an outsole layeror as an outer foam layer, is secured to the bladder element 16 so thatthe bladder element 16 rests on the additional sole layer 1886. Theadditional sole layer 1886 may also be referred to as an outer foamlayer as it is outward of the protrusions 1821 of the midsole layer1818, and further outward of a longitudinal centerline 1811 of themidsole assembly 1810 than the midsole layer 1818.

The additional sole layer 1886 can be a unitary layer that extendsbeneath and is secured to the bladder element 16. The additional solelayer 1886 can be a material similar to the midsole layer 1818, or arubber material, or a material such as used for a unisole. If theadditional sole layer 1886 is a material similar to the midsole layer1818, such as but not limited to foam, such as an EVA foam, then theadditional sole layer 1886 may function as a lower midsole layer. Forexample, the midsole layer 1818 and the additional sole layer 1886 canboth be an injected Phylon EVA foam. In one embodiment, the midsolelayer 1818 has a first density, and the additional sole layer 1886 has asecond density greater than the first density. By way of non-limitingexample, the specific density of the midsole layer 1818 may be 0.28 orgreater, but less than the specific density of the additional sole layer1886, which may be up to about 0.32 (with reference to water at 4degrees Celsius). By way of another further non-limiting example, thedurometer of the midsole layer 1818 and the additional sole layer 1886can both be between 52-58 on a durometer type C scale to measure Shorehardness (Asker C), with the durometer of the additional sole layer 1886greater than the durometer of the midsole layer 1818. If desired,additional harder outsole elements can be secured to a bottom surface ofthe additional sole layer 1886. One outsole element 1887A is shown inFIG. 44 secured to the additional sole layer 1886 in the heel region 28,and another outsole element 1887B is secured to the midsole layer 1810in the forefoot region 30. The outsole elements 1887A, 1887B can berubber or another durable material for these high wear areas.

The midsole layer 1818 is configured so that there is only a singleprotrusion 1821 at any lateral cross-section of the heel region 28, andthe single protrusion 1821 tapers laterally inward, away from the armportions of the bladder element 16 to the lowest extent 1825. Thisallows the bladder element 16 to distort inward under loading withoutinterference from the protrusion 1821. The lowest extent 1825 of theprotrusion 1821 in the heel region 24 terminates above the lowest extent1828 of the additional sole layer 1886 (i.e., a base of the additionalsole layer 1886) in the absence of at least the threshold loading forceacting to compress the midsole layer 1818. A distance D6 spaces thelowest extent 1828 of the additional sole layer 1886 from the lowestextent 1825 of the midsole layer 1818. The distance D6 thus alsorepresents the distance of the lowest extent 1825 of the protrusion 1821from the ground plane G. With this configuration, the protrusion 1821 inthe heel region 28 is not in operative contact with the ground plane Gin the absence of at least the threshold loading force on the midsolelayer 1818. As used herein, the protrusions 1821 are in “operativecontact” with the ground plane G when the protrusions 1821 directlycontact the ground plane G, assuming no additional outsole elements aresecured to the lowest extent 1825. If an additional outsole element issecured to the protrusion 1821, then the protrusion is in operativecontact with the ground plane G when the additional outsole elementcontacts the ground plane G so that the protrusion 1821 is thus inindirect contact with the ground plane G. In other words, the protrusion1821 positioned in the heel region 28 is not in operative contact withthe ground plane G until a loading force F is applied that is at least apredetermined threshold loading force that is sufficient to cause thelowest extent 1825 of the protrusion 1821 to contact the ground plane G,thus becoming part of the ground contact surface of the article offootwear 1812.

As shown in FIG. 46, lowest extents 1825B, 1825C of protrusions 1821 inthe forefoot region 30 are in operative contact with the ground plane Geven in the absence of the threshold loading force. In other words, thelowest extents 1825B, 1825C of the midsole layer 1818 and the lowestextent, or base surface 1828 of the additional outsole layer 1886 areflush with one another, at the ground plane G, in the forefoot region30. The additional sole layer 1886 is secured to the entire base surface190 of the bladder element 16 by bonding, adhesives, welding, or thelike, and is in operative contact with the ground plane G even in theabsence of the threshold loading force.

During application of at least a threshold loading force, a first stageof attenuation of the force occurs prior to operative contact of theprotrusion 1821 in the heel region 28 with the ground plane G. Duringthe first stage of attenuation, the harder additional sole layer 1886and the bladder element 16 attenuate the force in the heel region 28,with the midsole layer 1818 in the forefoot region 30 attenuating someof the loading force F. A second stage of attenuation occurs in the heelregion 28 as the midsole layer 1818 moves downward and the lowest extent1825 of the protrusion 1821 moves into operative contact with the groundplane G. During the second stage, the protrusion 1821 in the heel region28 has moved into operative contact with the ground plane G, so that theloading force F is attenuated both by the protrusion 1021 and by thebladder element 16 in the heel region 28.

The midsole assembly 1810 can be tuned during the design of the assembly1810 to provide a desired underfoot feel by selecting the geometry ofthe protrusions 1821, the distance D6, and the selection of materialsfor the midsole layer 1818 and the additional sole layer 1886. Theseparameters can be selected to cause the first stage of attenuation tohave a first energy absorbing characteristic, and the second stage ofattenuation to have a second energy absorbing characteristic. Forexample, the rate of compression of the midsole assembly 1810 may bedifferent in the different stages of attenuation. Additionally, when theprotrusions 1821 contact the ground, a greater tactile underfoot feel isexperienced by a wearer of the article of footwear 1012, which may bedesirable.

FIG. 47 shows a top surface 1891 of the midsole layer 1818, andindicates that the top surface 1891 can optionally be configured withrecesses 1892A, 1892B configured to retain ambient bladder elements1893A, 1893B to provide additional localized cushioning. The bladderelements 1893A, 1893B may also be referred to as ambient pods, and areformed from the same materials used to construct the bladder element 16,but configured as unpressurized, sealed chambers. Alternatively, therecesses 1892A, 1892B can be empty, and sealed by an overlaying foamlayer (not shown), similar to the recesses 74B, 74C of FIG. 1.

Optionally, a plate 1894 can be molded to the bladder element 16, suchas by co-molding during thermoforming of the bladder element 16. Theplate 16 can extend between the arm portions 26A, 26B in the forefootregion 30. The plate 1894 can be a relatively stiff material, such as athermoplastic elastomer, or a urethane coated carbon fiber. The plate1894 increases the stiffness of the forefoot region 30, creating a highpropensity for the flexing of the forefoot region 28 or the midfootregion 32 to cause “snap-back”, or return of the midsole assembly 1810to an unflexed position following flexing.

Referring to FIGS. 48-50, a portion of an article of footwear 1912 isshown that includes a midsole assembly 1910 with a fluid-filled bladderelement 16 as described with respect to FIG. 1. The bladder element 16is arranged so that the substantially arc-shaped heel portion 24 ispositioned in a heel region 28 of the article of footwear 1912, and thearm portions 26A, 26B extend from the heel region 28 to the forefootregion 30 along a peripheral region 22. The article of footwear 1912 hasa heel region 28, a forefoot region 30, and a midfoot region 32corresponding with portions of a human foot as described with respect tosimilar regions of the midsole layer 14 of FIG. 2.

The midsole assembly 1910 includes a resilient midsole layer 1918 thatis secured to and rests on the bladder element 16 as shown in FIGS. 49and 50. The midsole layer 1918 has protrusions 1921 that descend from alower portion of the midsole layer 1918 into a cavity 1923 between thearm portions 26A, 26B. The midsole layer 1918 may be referred to as aninner foam layer as it extends inward of the bladder element 16. Anadditional sole layer 1986, which may be referred to as an outsole layeror as an outer foam layer, is secured to the bladder element 16 so thatthe bladder element 16 rests on the additional sole layer 1986. Theadditional sole layer 1986 may also be referred to as an outer foamlayer as it is outward of the protrusions 1921 of the midsole layer1918, and further outward of a longitudinal centerline 1911 of themidsole assembly 1910 than the midsole layer 1918.

The additional sole layer 1986 can be a unitary layer that extendsbeneath and is secured to the bladder element 16. The additional solelayer 1986 can be a material similar to the midsole layer 1918, or arubber material, or a material such as used for a unisole. If theadditional sole layer 1986 is a material similar to the midsole layer1918, such as but not limited to foam, such as an EVA foam, then theadditional sole layer 1986 may function as a lower midsole layer. Forexample, the midsole layer 1918 and the additional sole layer 1986 canboth be an injected Phylon EVA foam. In one embodiment, the midsolelayer 1918 has a first density, and the additional sole layer 1986 has asecond density greater than the first density. By way of non-limitingexample, the specific density of the midsole layer 1918 may be 0.28 orgreater, but less than the specific density of the additional sole layer1986, which may be up to about 0.32 (with reference to water at 4degrees Celsius). By way of another further non-limiting example, thedurometer of the midsole layer 1918 and the additional sole layer 1986can both be between 52-58 on a durometer type C scale to measure Shorehardness (Asker C), with the durometer of the additional sole layer 1986greater than the durometer of the midsole layer 1918. If desired,additional harder outsole elements can be secured to a bottom surface ofthe additional sole layer 1986.

The midsole layer 1918 is configured so that the lowest extent 1925 ofeach protrusion 1921 in the heel region 24 terminates above the lowestextent 1928 of the additional sole layer 1986 (i.e., a base of theadditional sole layer 1986) in the absence of at least the thresholdloading force acting to compress the midsole layer 1918. A distance D7spaces the lowest extent 1928 of the additional sole layer 1986 from thelowest extent 1925 of the midsole layer 1918. The distance D7 thus alsorepresents the distance of the lowest extent 1725 of the protrusion 1921from the ground plane G. With this configuration, the protrusions 1921in the heel region 28 are not in operative contact with the ground planeG in the absence of at least the threshold loading force on the midsolelayer 1918. As used herein, the protrusions 1921 are in “operativecontact” with the ground plane G when the protrusions 1921 directlycontact the ground plane G, assuming no additional outsole elements aresecured to the lowest extent 1925. In other words, the protrusion 1921positioned in the heel region 28 is not in operative contact with theground plane G until a loading force F is applied that is at least apredetermined threshold loading force sufficient to cause the lowestextent 1925 of the protrusion 1921 to contact the ground plane G, thusbecoming part of the ground contact surface of the article of footwear1812. If an additional outsole element is secured to the protrusion1921, then the protrusion is in operative contact with the ground planeG when the additional outsole element contacts the ground plane G sothat the protrusion 1921 is thus in indirect contact with the groundplane G.

As shown in FIG. 50, lowest extents 1925B, 1925C of protrusions 1921 inthe forefoot region 30 are in operative contact with the ground plane Geven in the absence of the threshold loading force. In other words, thelowest extents 1925B, 1925C of the midsole layer 1918 and the lowestextent, or base surface 1928 of the additional outsole layer 1986 areflush with one another, at the ground plane G, in the forefoot region30. The additional sole layer 1986 is secured to the entire base surface190 of the bladder element 16 by bonding, adhesives, welding, or thelike, and is in operative contact with the ground plane G even in theabsence of the threshold loading force.

During application of at least a threshold loading force, a first stageof attenuation of the force occurs prior to operative contact of theprotrusions 1921 in the heel region 28 with the ground plane G. Duringthe first stage of attenuation, the harder additional sole layer 1986and the bladder element 16 attenuate the force in the heel region 28,with the midsole layer 1918 in the forefoot region 30 attenuating someof the loading force F. A second stage of attenuation occurs in the heelregion 28 as the midsole layer 1918 moves downward and the lowest extent1925 of the protrusions 1921 move into operative contact with the groundplane G. During the second stage, the protrusions 1921 in the heelregion 28 have moved into operative contact with the ground plane G, sothat the loading force F is attenuated both by the protrusions 1921, andby the bladder element 16 in the heel region 28.

As best shown in FIGS. 49 and 50, the resilient midsole layer 1918 andthe bladder element 16 are configured so that a first portion 1957 ofthe resilient midsole layer 1918 adjacent the inward-facing surface 80of the bladder element 16 is secured to the bladder element 16 such asby welding, bonding, or the like. A second portion 1959 of the resilientmidsole layer 1918 adjacent the inward-facing surface 80 of the bladderelement is spaced from the bladder element 16 when the threshold loadingforce is not applied to the resilient midsole layer 1918. In otherwords, as shown in FIG. 49, the second portion 1959 of each protrusion1921 is spaced from the inward-facing surface 80 of the bladder element16. The spacing of the second portion 1959 is due to the angling of thesecond portion 1959 inward toward the center of the midsole layer 1918relative to the first portion 1957. The second portion 1959 has asurface profile 1961A that is substantially identical to a surfaceprofile 1961B of the portion of the inward-facing surface 80 of thebladder element 16 that is adjacent to the second portion 1959.

Due to the flexible and resilient properties of the midsole layer 1918,under at least the threshold loading force, compression of the midsolelayer 1918 9 causes the second portions 1959 to move into contact withthe inward-facing surface 80 of the bladder element 16, similar to themidsole layer 1018 of FIG. 26.

The midsole assembly 1910 can be tuned during the design of the assembly1910 to provide a desired underfoot feel by selecting the geometry ofthe protrusions 1921, the distance D7, the second portions 1959 and theselection of materials for the midsole layer 1918 and the additionalsole layer 1986. These parameters can be selected to cause the firststage of attenuation to have a first energy absorbing characteristic,and the second stage of attenuation to have a second energy absorbingcharacteristic. For example, the rate of compression of the midsoleassembly 1910 may be different in the different stages of attenuation.Additionally, when the protrusions 1921 contact the ground, a greatertactile underfoot feel is experienced by a wearer of the article offootwear 1912, which may be desirable. The midsole layer 1918 could beconfigured with recesses similar to recesses 1892A, 1892B for forming orsupporting ambient pods. The midsole layer 1918 could also have a platesimilar to plate 1894 in the forefoot region 30 to increases thestiffness of the forefoot region 30, create a high propensity for theflexing of the forefoot region 28 or the midfoot region 32 to cause“snap-back”, or return of the midsole assembly 1910 to an unflexedposition following flexing.

While several modes for carrying out the many aspects of the presentteachings have been described in detail, those familiar with the art towhich these teachings relate will recognize various alternative aspectsfor practicing the present teachings that are within the scope of theappended claims. It is intended that all matter contained in the abovedescription or shown in the accompanying drawings shall be interpretedas illustrative only and not as limiting.

1. An article of footwear having a heel region, a forefoot region, and aperipheral region; and the article of footwear comprising: a midsoleassembly having: a fluid-filled bladder element having a substantiallyarc-shaped heel portion, a lateral arm portion, a medial arm portionspaced from the lateral arm portion, each of the lateral and medial armportions extending from the heel portion, and the bladder elementconfigured to be positioned with the heel portion in the heel region andthe lateral and medial arm portions extending from the heel region tothe forefoot region along the peripheral region; a midsole layer securedto and resting on the bladder element and having multiple protrusionsdescending into a cavity formed between the lateral and medial armportions; wherein a lowest extent of each of said multiple protrusionsterminates above a base surface of the bladder element; and an outsolesecured to the base surface of the fluid-filled bladder element andhaving extension portions secured to the multiple protrusions such thatthe extension portions are excluded from the ground contact surface ofthe article of footwear in the absence of at least a threshold loadingforce on the midsole assembly.
 2. The article of footwear of claim 1,wherein the lateral and medial arm portions have terminal endspositioned in the forefoot region.
 3. The article of footwear of claim1, wherein the midsole layer has a flex groove extending generallylengthwise and positioned between at least some of the multipleprotrusions.
 4. The article of footwear of claim 3, wherein the midsolelayer has laterally-extending grooves between at least some of themultiple protrusions.
 5. The article of footwear of claim 1, wherein: afirst portion of the midsole layer adjacent to an inward-facing surfaceof the bladder element is secured to the bladder element; and a secondportion of the midsole layer adjacent to the inward-facing surface ofthe bladder element is spaced from the bladder element in the absence ofat least the threshold loading force and is configured to move intocontact with the inward-facing surface of the bladder element undercompression by the threshold loading force to attenuate the thresholdloading force.
 6. The article of footwear of claim 5, wherein the secondportion has a surface profile in the absence of at least the thresholdloading force that is substantially identical to a surface profile ofthe inward-facing surface of the bladder element.
 7. The article offootwear of claim 6, wherein: the extension portions of the outsole areconfigured to move into contact with the ground plane to become part ofthe ground contact surface of the article of footwear only after thesecond portion of the midsole layer moves into contact with theinward-facing surface of the bladder element; and the midsole assemblyprovides a first stage of attenuation of the loading force when thesecond portion of the midsole layer moves into contact with theinward-facing surface of the bladder element, and provides a secondstage of attenuation of the loading force when the extension portions ofthe outsole move into operative contact with the ground plane.
 8. Thearticle of footwear of claim 1, wherein: the bladder element tapers fromthe base surface to a peak extending along the bladder element oppositethe base surface; the bladder element has a generally outward-facingside surface between the base surface and the peak, and a generallyinward-facing side surface between the base surface and the peak; andthe midsole layer is supported on the inward-facing side surface so thatat least a portion of the outward-facing side surface of the bladderelement is exposed.
 9. The article of footwear of 1, wherein the bladderelement is substantially transparent.
 10. The article of footwear ofclaim 1, wherein the outsole has a peripheral portion that extendsaround the forefoot region, the midfoot region, and the heel region atboth a medial side and a lateral side of the outsole, and the extensionportions extend laterally inward from the peripheral portion.
 11. Thearticle of footwear of claim 10, wherein the multiple protrusions aredisposed in the forefoot region, the midfoot region, and the heelregion.
 12. The article of footwear of claim 10, wherein the extensionportions extend upward from the peripheral portion in the absence of atleast the threshold loading force.
 13. The article of footwear of claim10, wherein: the midsole layer has a flex groove extending generallylengthwise from the forefoot portion to the heel portion on a bottomsurface of the midsole layer and positioned between at least some of themultiple protrusions; and the midsole layer has laterally-extendinggrooves extending generally laterally on the bottom surface of themidsole layer, each of the laterally-extending grooves disposed betweenadjacent protrusions of the multiple protrusions.
 14. The article offootwear of claim 13, wherein the flex groove increases in width underthe threshold loading force.
 15. The article of footwear of claim 10,wherein the outsole is a unitary, one-piece outsole defining an openingextending completely through the outsole between the extension portions.16. An article of footwear having a heel region, a forefoot region, anda peripheral region; and the article of footwear comprising: a midsoleassembly having: a fluid-filled bladder element having a substantiallyarc-shaped heel portion, a lateral arm portion, a medial arm portionspaced from the lateral arm portion, each of the lateral and medial armportions extending from the heel portion, and the bladder elementconfigured to be positioned with the heel portion in the heel region andthe lateral and medial arm portions extending from the heel region tothe forefoot region along the peripheral region; a midsole layer securedto and resting on the bladder element and having multiple protrusionsdescending into a cavity formed between the lateral and medial armportions; wherein a lowest extent of each of said multiple protrusionsterminates above a base surface of the bladder element; and an outsolesecured to the base surface of the fluid-filled bladder element andhaving extension portions secured to the multiple protrusions such thatthe extension portions are excluded from the ground contact surface ofthe article of footwear in the absence of at least a threshold loadingforce on the midsole assembly; wherein a first portion of the midsolelayer adjacent to an inward-facing surface of the bladder element issecured to the bladder element; wherein a second portion of the midsolelayer adjacent to the inward-facing surface of the bladder element isspaced from the bladder element in the absence of at least the thresholdloading force and is configured to move into contact with theinward-facing surface of the bladder element under compression by thethreshold loading force to attenuate the threshold loading force; andwherein the outsole has a peripheral portion that extends around theforefoot region, the midfoot region, and the heel region at both amedial side and a lateral side of the outsole, the extension portionsextend laterally inward from the peripheral portion, and the outsole isa unitary, one-piece outsole defining an opening extending completelythrough the outsole between the extension portions.
 17. The article offootwear of claim 16, wherein: the midsole layer has a flex grooveextending generally lengthwise from the forefoot portion to the heelportion on a bottom surface of the midsole layer and positioned betweenat least some of the multiple protrusions; and the midsole layer haslaterally-extending grooves extending generally laterally on the bottomsurface of the midsole layer, each of the laterally-extending groovesdisposed between adjacent protrusions of the multiple protrusions. 18.The article of footwear of claim 17, wherein the flex groove increasesin width under the threshold loading force.
 19. The article of footwearof claim 16, wherein the midsole layer has laterally-extending groovesbetween at least some of the multiple protrusions.